England winger Chris Ashton grabbed the crucial try as Aviva Premiership leaders Saracens fought back from 13-0 down to beat Wasps 22-13.

Saracens scored all their points in the opening 13 minutes with full-back Elliot Daly landing two long-range penalties either side of a try from 21-year-old winger Christian Wade which was converted by Stephen Jones.

However, Saracens hit back almost immediately with a try from USA international Chris Wyles and a penalty from Owen Farrell saw them go into the interval 13-8 behind. The visitors then completed their comeback in the second half thanks to Ashton's 66th-minute score and three more Farrell penalties.

Wasps director of rugby Dai Young had shuffled his front row and called for an improvement in the scrum following last weekend's home defeat by Northampton. His pack responded as early as the eighth minute, forcing the back-pedalling Saracens scrum to concede a penalty, kicked by long-range specialist Daly from a metre inside the Sarries' half.

Wasps struck again two minutes later when Wade intercepted a sloppy pass from Charlie Hodgson and raced 60 yards for his 10th Premiership try of the season, boosting his claim for a place on England's summer tour to Argentina.

It was converted by Jones and the home side made it 13-0 after Saracens' centre Joel Tomkins was penalised for a late tackle on the former Wales fly-half after he had launched a big clearance kick into the opposing half. The penalty was awarded where the ball landed and Daly made no mistake with an excellent angled kick from 40 metres.

But Wasps spoilt their good start when their defence was caught napping. They were expecting Saracens to go for goal but England full-back Alex Goode suddenly took a quick tap and made the break to send Wyles, called up to replace injured winger David Strettle, over in the left corner.

Farrell missed the conversion and was then wide with his kick after the Saracens pack wheeled a scrum, forcing Wasps to concede a penalty, but the England fly-half, switched to inside centre with his international team-mate Brad Barritt rested, made amends in the 26th minute by landing a 38-metre penalty.

Saracens should have drawn level in the 36th minute when England prop Mako Vunipola - whose brother Billy lined up at number eight for Wasps - dived for the line and stretched one-handed to touch down, only for his international colleague Joe Launchbury to produce a timely intervention and knock the ball away.

The visitors suffered another blow a minute before half-time when lock Mouritz Botha was sin-binned for disrupting a Wasps attack with a deliberate knock-on. Wasps failed to capitalise on their 10-minute, one-man advantage before Botha returned, though.

Back to full strength, Saracens put Wasps under pressure but Vunipola squandered a second try-scoring opportunity when he knocked on with the line at his mercy.

However referee Martin Fox, who had played advantage following a previous offence, brought play back for the 61st-minute penalty, kicked by Farrell to cut the gap to two points. Ashton put Saracens ahead for the first time in the 66th minute when he latched on to a through-kick from Goode and, despite the attentions of Daly, touched down in the right-hand corner for his fourth Premiership try of the campaign.

Farrell missed the conversion - his third failure from five kicks - but succeeded with his third penalty after Billy Vunipola was sin-binned for a deliberate knock-on in front of his own posts.

He added a fourth two minutes from time to complete the scoring when Wasps illegally pulled down a Saracens' maul two metres from the line.

Saracens coach Mark McCall was quick to praise try-scorer Chris Ashton, who has come in for criticism following mixed displays for England in the Six Nations.

"I thought he was absolutely brilliant today," said McCall. "It was the Chris Ashton everybody talked about two years ago, popping up all over the place, hands on the ball, making breaks, but he also defended very well, he was hungry for work, he was energetic so it was great for him.

"He's a sensitive soul and anyone in the world who is sensitive is going to be affected a little bit by some of the criticism he received. At our club we try to concentrate on what people are good at rather than what they are not good at - and Chris is good at quite a few things."

Wasps' director of rugby Dai Young was disappointed with his side's inability to control the match, despite racing to a 13-0 lead early on.

"We started well but it's very difficult to play without the ball," Young said. "For big periods of the game, our handling and ball retention was really poor. We had something like 16 handling errors which meant we never really worked Saracens hard enough in defence to stress them. If you give the top teams that amount of ball in that territory they are always going to come away with points."