Gregor Townsend admitted that on their day, Saracens may be an unbeatable side after they brushed aside his Glasgow Warriors side to reach the European Champions Cup semi-finals courtesy of a 38-13 victory at Allianz Park.

The reigning European champions ran in four tries as they once again found their stride, just a week after putting 50 points past Bath here in North London. Having suffered something of a blip in the Premiership during the last two months as they dropped from the top of the tree to third, the return of their international contingent looks to have returned them to the heady heights they hold themselves by.

Had Townsend been asked about that before kick-off, the soon-to-be Scotland head coach would have claimed any game is winnable, but after watching Chris Ashton score two tries against his side along with further scores from Marcelo Bosch and Brad Barritt, he was no longer so sure after the quarter-final defeat.

“A French journalist spoke to me at the beginning of the year and said ‘Saracens are going to win in Europe, they’re just unbeatable’ and I thought ‘what? Surely every game is a winnable one’,” Townsend said. “The view from their side, maybe that was just one French journalist or the view from French rugby, but when you see them like that today they’re very difficult to beat and they’ve certainly expanded their game as well.

“We saw that last week against Bath and today, the ratio of driven lineouts to off the top was much less than I had been in their league games, maybe because of the weather or maybe because of league games. Of course, they’re looking to bring players into play and they got their back three on the ball a lot today and they were excellent.”

One of those back-three was, of course, Ashton, and the exiled England wing scored twice for the second week in succession to not only pave the way for Saracens’s progression to the last four – where they will take on Munster – but also equal Vincent Clerc’s all-time record 36 tries in European competition.

“I thought his all-round game was really strong today: good in the air, good defensively, and we gave him enough chances to score a couple,” said the Saracens director of rugby Mark McCall. “It’s great that he took the chances he did.”

British and Irish Lions captain candidates Show all 6 1 /6 British and Irish Lions captain candidates British and Irish Lions captain candidates Alun Wyn Jones Jones is probably still the leading candidate for the captaincy, even if his, and Wales’, Six Nations was not what they were hoping for. Jones took the Welsh armband from Sam Warburton for the championship but at times looked uneasy at making a call, such as when he was overruled when Wales opted to go for the corner against Scotland, rather than taking the shot at three points. Jones captained the Lions in the deciding third Test against Australia in 2013 and is a guaranteed starter if fit – something Gatland is keen for his captain to be, although not a necessity. AFP/Getty Images British and Irish Lions captain candidates Sam Warburton Had Wales not finished fifth in the championship with three defeats, there is a good chance Warburton would have been named player of the tournament. The way he reacted to losing the Wales captaincy and moving to blindside flanker has been phenomenal and he is now the bookies’ favourite after his performances and having already led the Lions to a tour victory. Of Warburton’s chances, Gatland said: “He's a different captain to some other players. He leads by example. He doesn't say a lot but he has had that experience. He's one of the guys potentially in contention, definitely.” However, he has been so good without the burden of the armband, would giving it to him hinder his performances? Getty Images British and Irish Lions captain candidates Dylan Hartley Before his red card for Northampton in December, Hartley was the frontrunner for the armband but now his place on the plane is not even assured. For England, Jamie George has impressed and could usurp his captain’s position over the next 12 months, with Hartley arguably not even the third most impressive Hooker the home nations boasted during this year’s Six Nations. However, his grit and fire has been one of the reasons for England’s success under Eddie Jones and it is that sort of personality which could be vital in the hotbed of New Zealand. Getty Images British and Irish Lions captain candidates Rory Best The way Best led Ireland to ending England’s unbeaten run shows that he has the ability to motivate the players around him in tough and gritty situations. He has also captained a side to a win over the All Blacks, the only candidate who is able to say that. Best is certainly a viable candidate but the question mark that remains hanging over him is if he is good enough to start at hooker against the All Blacks? Hartley, Best, George and Wales’ Ken Owens are all in with a shout. AFP/Getty Images British and Irish Lions captain candidates Owen Farrell Farrell was player of the tournament after a stunning Six Nations. His kicking is up there with Leigh Halfpenny’s as amongst the best in the world and he has the right mentality of a captain having been schooled under Eddie Jones. Farrell looks certain to start at 12 for the Lions and would make a fierce captain. However, having not captained an international side from the start, how would he fare leading the most intense tour the Lions have embarked on? It is a tough challenge for the most weathered of captains, never mind a novice. AFP/Getty Images British and Irish Lions captain candidates Conor Murray An outside shout for captain but the way he controls the game from around the ruck shows his importance to the Lions. He, like Best, has experience of beating the All Blacks and of a winning Lions Tour (like everyone on this list, other than Hartley). He has captaincy experience but while he was a certain starter a month ago, the performances of Rhys Webb have given Gatland a real decision to make. He said he wants to pick his squad first and then his captain and that could go against Murray in the decision-making process if Webb is now considered ahead of him. Getty

McCall now faces the prospect of preparing his side for a trip to Dublin to face Munster in the semi-final, something that will feel all too familiar for many of his players after England’s Grand Slam-miss three weeks ago in the Six Nations. The emotion of 50,000 fans inside the Aviva Stadium will be enough to humble most teams, but Munster will also be powered by the emotion of the passing of their former head coach, Anthony Foley, who died suddenly last October during the current campaign, and the determination to do the former Ireland forward the ultimate tribute.

“The players don't realise it yet, but hopefully they will when they get there, it's going to be a very special day,” McCall added. “We played Clermont a couple of years ago when there were 30,000 Clermont fans and us. That was different, but this is going to be double that – there will be 50,000 Munster fans.

Chris Ashton matched Vincent Clerc's record of 36 European tries (Getty)

“We all know there's an emotional element to this game and we have to make sure we're able to cope with that. Doing that will be one of our tasks over the next few weeks.