Scrum-half skulduggeryRugby must be vigilant to prevent the cynicism so prevalent in football from creeping into the sport.Football has belatedly – by about 30 years – responded to acts of simulation by bringing in bans from next season for those who dive. But it will find it harder to combat the chronic problem of attackers choosing to make contact with defenders so as to dupe the referee into giving a penalty.A near equivalent in rugby is a defender choosing to run into an attacker and then claiming he was prevented from making a tackle on a ball-carrier. I haven’t seen anyone do this yet but you sense it’s going to happen.Naughty! Crusaders scrum-half Bryn Hall was told off for trying to extract penalties in Suva (Getty)Chiefs hooker Nathan Harris tried to claim he was obstructed in the play that brought a try for Crusaders’ Heiden Bedwell-Curtis, but in fairness he was marginally hampered by Owen Franks.In the same match, referee Mike Fraser felt obliged to warn both scrum-halves for deliberately passing the ball at an opponent on the wrong side in order to draw a penalty. This is a habit that’s on the increase and well done Fraser for telling the No 9s to cut it out.On a positive note, how fantastic that Chiefs took the fixture to Suva (as last year) so that Fijians could watch top-class Super Rugby on their doorstep. They were queuing outside before the gates opened and a crowd of 17,000 showed what an appetite there is for New Zealand rugby on the islands.Davies indisciplineYou might think I would chastise Steff Evans for the tip tackle on Garry Ringrose that jeopardized the Scarlets’ hopes of winning their Guinness Pro12 semi-final. But no, that is to some extent an occupational hazard.Body blow: Marius Mitrea sends off Steff Evans but Scarlets still won in Dublin (Huw Evans Agency)Instead, I’m highlighting the daft indiscipline by Gareth Davies that preceded that passage of play. With Scarlets poised to have an attacking five-metre scrum, the scrum-half initiated a tussle with Johnny Sexton and was penalised, gifting Leinster a pressure-relieving clearance to touch. TAGS: HighlightScarlets Sizzling Scarlets take top billing on a semi-final weekend to savour, Scotland reign at Twickenham and a hammer blow for the Lions as Billy Vunipola pulls out the tour THE SAINTSScarlets’ history makersBilly Vunipola’s injury cast a cloud over a weekend of four huge club semi-finals – and three of them proved to be belters. Pride of place goes to the Scarlets (27-15 at Leinster) for becoming the first team to win an away semi in the Guinness Pro12 play-offs.It’s not being wise after the event to say that their 5-1 odds were overly generous, because the Scarlets had only lost one of their previous 11 league games and were scoring tries for fun. Nevertheless, that one blot was a 45-9 rout in Dublin in round 17 and the expectation was that Leinster’s pack, with two Lions props to the fore, would deny Wayne Pivac’s side a platform to play off.Up the reds: the Scarlets celebrate their backs-to-the-wall 14-man victory against Leinster (Inpho)In the event, the home side never really got going; perhaps they were shell-shocked by the stunning handling and offloading that conjured tries for Steff Evans, Aaron Shingler and Gareth Davies in the first half-hour.After Steff Evans’s red card, openside James Davies filled in at left-wing and finished Man of the Match for a performance that included three precious turnovers.“If we had a choice of him over other opensides in the country we would take James every day,” said Pivac. “If you put him on the wing he doesn’t flinch, he just goes out there and does the job. He has a great skill-set and a very big heart.”Zebo’s cookingScarlets, whose only Pro12 title was in 2004, will face three-time champions Munster at Aviva Stadium on Saturday (6.15pm).Munster’s 23-3 defeat of Ospreys was more mundane but did feature a classic counter-attack try by Simon Zebo after Justin Tipuric’s clearing kick seemed to have ended the danger. Keith Earls fielded it and combined with Andrew Conway and Francis Saili to put Zebo over for the game’s outstanding moment.Classic try: Tom Habberfield and Dan Evans can’t prevent Simon Zebo scoring for Munster (Inpho)“Turning and burning” was Zebo’s phrase for it after the game, when he also explained his ‘stirring the pot’ try celebration. It’s borrowed from basketball star James Harden and means something’s cooking!Slade’s perfect puntThere was a time when I was convinced that Exeter’s Henry Slade should have been the first name on England’s team sheet. Now 24, he suffered a broken leg and hasn’t quite pushed on but he remains a formidable talent, and one with time to win 100 caps (he has 95 to go).It says much for the depth of Exeter’s resources that they can afford to leave him on the bench for an Aviva Premiership semi-final but Slade came on to make a difference.The 60-metre touch-finder he delivered at the end of Chiefs’ 18-16 win over Saracens was a thing of beauty. “One of the great kicks of all time” was how Sarries DoR Mark McCall graciously described it and it gave Chiefs the field position from which they drove over the line and Sam Simmonds scored the winning try. With Exeter City playing a Wembley final on Sunday, expect hordes of Devonians to invade the capital.Leaving it late: Sam Simmonds’s try puts Exeter into their second successive Premiership final (Getty)Was this Exeter’s greatest-ever victory? It’s hard to disagree. They played really high-quality phase rugby, with almost no errors, and even then they only just won. That tells you how good this Saracens team is, because a normal team would have wilted under the pressure.The result was an excellent one for the Lions because Sarries’ five remaining Lions will be spared another huge game ahead of the departure to New Zealand.Before Billy Vunipola’s withdrawal (see below), I felt there was a strong chance that all five of Saracens’ Lions forwards could make the Test pack to face the All Blacks. Now it can only be four – Maro Itoje, George Kruis, Mako Vunipola and Jamie George – but for one club that could still be called greedy!Eighty and out for AshIt was a pity that Chris Ashton didn’t get the farewell he deserved, the Saracens wing taking his leave just ten minutes into the match.Only Tom Varndell and Mark Cueto have scored more tries than the Toulon-bound former rugby league man, who finishes his Premiership career with 80 in 131 games, the first 33 of them scored for Northampton.Where it began: Chris Ashton on his way to his very first Premiership try, for Saints in 2008Not everyone cares for his ostentatious finishing (for me, the Ash Splash adds colour) but he has been a wonderful addition to English domestic rugby, with his tracking of the ball changing the way union wings play the game.Right result at the RicohTrying to prevent Exeter’s first English title will be Wasps, the latest of whose six triumphs was nine years ago. Their helter-skelter 21-20 win over Leicester included a four-minute uninterrupted passage of play (66-70 minutes) that almost brought players to their knees.Defiantly heroic though Tigers were, Wasps deserve to be lining up in Saturday’s Twickenham final (2.30pm) after scoring 89 tries and 13 try bonus points during the regular season. Only Exeter (86 and 15) can match that attacking potency.Strong guy: Guy Thompson has Tigers’ defence in a muddle during a cracking semi at Wasps (Getty)Scots do it again Counted out: Billy Vunipola goes down with the injury that has cost him a Lions tour place (Getty Images) Amid all the club drama, there was plenty to celebrate in sevens. In the HSBC London Sevens that concluded this season’s world series, Scotland retained their London title with a 12-7 defeat of England in the final, captain Scott Riddell scoring the winning try.The Scots, who had also reached the Paris final a week earlier, pulled off an extraordinary win over New Zealand in the quarter-finals. They trailed 21-0 at half-time and had got back to 21-17 when an assistant referee spotted that the Kiwis had eight men on the field during a substitution – a mistake they also made in Sydney last year.Jamie Farndale crossed from the penalty to give Scotland victory by 24-21.London calling: Scotland Sevens celebrate retaining their London title at Twickenham (Getty)England, who were handicapped by injuries to Tom Mitchell, Dan Bibby and Ollie Lindsay-Hague, still came close to winning the cup and their second-place finish in the series is their best since 2006, when their current coach Simon Amor was the captain.Dan Norton, the all-time record try-scorer in the series with 261, scored a sensational try in the final when he ran through most of the Scotland team and sat George Horne down with a delicious final piece of footwork.But biggest plaudits go to South Africa, who reached eight of the ten cup finals over the season, winning five of them, to secure their second series crown (after 2008-09).They will be favourites for the 2017-18 series that includes a new venue in Hamilton and will be followed by the 2018 Sevens World Cup in San Francisco on 20-22 July, tickets for which will go on general sale exactly one year before the tournament.THE SINNERSBilly’s bad shoulderOnly one place to start – the shuddering news that England No 8 Billy Vunipola has withdrawn from the Lions tour with a shoulder injury.It’s stating the obvious to say that the worthy James Haskell is not a like-for-like replacement because there is no one like big Billy.Running repairs: Vunipola during the defeat at ExeterIt’s not just that he can carry the ball into contact with two or three defenders and yet still it looks like he’s the one doing the bullying. Against Exeter on Saturday he won a huge turnover when Saracens were under the cosh just before half-time, and later he produced a remarkable ripped steal as the Chiefs thundered forward from a driving maul.He is a big-game player, a Test-match animal to use Ian McGeechan’s phrase, and irreplaceable. He would have been a shoo-in for the Lions Test No 8 shirt that will now be contested by CJ Stander and Taulupe Faletau. LATEST RUGBY WORLD MAGAZINE SUBSCRIPTION DEALS As everyone knows, matches and momentum can swing on such moments. Gareth, if Conor Murray has the ball during a pause in play on Saturday, don’t go waving your arms near his face!For the latest Rugby World subscription offers, click here.