Wasps make another error, as an offside at the breakdown following the restart gives Sarries a penalty.

They kick all the way up to the Wasps 22 thanks to a brilliant long kick from Owen Farrell.

A change for Sarries at the break.

Saracens number eight Billy Vunipola has been replaced by Michael Rhodes.

Big Billy has been impressive on his return from a hamstring injury.

Wasps get the second half started.

Maybe Dai Young has been chanelling Popeye and force-feeding his side spinach at the break.

But will Wasps continue to wilt under the north London sun, or will they come steaming back into the game?

Jeremy Guscott
Ex-England centre on BBC Radio 5 live sports extra

Wasps have had no answer to slowing down Sarries' quick ball, which is a surprise - they seem weak in the forward pack.

The line-out is such an important part of the game and if you can't get that steady then you are going to struggle.

As Danny Ciprini said earlier, you need a pack on spinach.

James Haskell, who's leaving Wasps for Northampton Saints at the end of the season, isn't in action at Allianz Park this afternoon because of injury...

Image source, Getty Images

... So he's popped along to some wedding that's going on at Windsor Castle. Because what else would he be doing on a Saturday afternoon, right?

By the way, for those of you purposefully avoiding it, you'll be pleased to know the ceremony is over!

Of course, we're still only a quarter of the way through Premiership semi-finals day.

After the match at Allianz Park, reigning champions Exeter Chiefs host Newcastle Falcons for the right to play the victor here at Twickenham in a week's time.

Kick-off at Sandy Park is 15:30 BST and we'll have live text and radio commentary of that one too.

Sarries have the upper hand in today's first Premiership semi-final thanks to Alex Lozowski's score inside 94 seconds and a second from Vincent Koch.

Owen Farrell has been flawless from the kicking tee, adding both conversions and three penalties.

Wasps though got a lifeline when Willie Le Roux crossed, but need a much better performance in the second half if they are to keep alive their hopes of a place in the final at Twickenham.

Image source, Getty Images

A scrappy passage from the resulting Sarries line-out is eventually ended, and JP Doyle blows the whistle for half-time.

A loose pass puts Jimmy Gopperth under pressure but somehow Wasps survive and break out of their own 22.

A grubber kick is put forward by Thomas Young but it bounces into touch to the frustration of the flanker and the visiting team.

A decent turn of pace from Christian Wade takes Wasps over halfway. They go through six phases but Sarries turn the ball over once again and push Wasps back.

Jack Willis is back on his feet and is being helped off the pitch to applause from the crowd.

He won't be able to continue, and Guy Thompson is on in his place.

England coach Eddie Jones may be watching on with some concern, with Willis named in the squad for the tour of South Africa this summer.

There could be a bit of a break in play here as Jack Willis needs treatment on that injury.

He was clasping his right knee and the Wasps forward looks in some discomfort.

Replays show it's a slight hyper-extension, and the physios are doing a few stretches on his leg.

Wasps steal the Saracens line-out - the first time they have managed to do that today.

But the good feeling doesn't last long as Saracens win a penalty back at the breakdown.

They take it quickly but the move breaks down, and Wasps flanker Jack Willis needs treatment for an injury.

Wasps spread it left and then back over to the right, before Christian Wade is bundled into touch by Chris Wyles on halfway.

Good defence from Saracens there, keeping it tight with just a few minutes left before the break.

Ben Harris is back on in the Wasps front row after his head injury assessment, with Matt Mullan trotting off.

Wasps come away with the ball from the scrum and work their way up to their 10-metre line.

But Sarries are making them work for every inch and are doing a decent job in slowing them down.

The ball is eventually knocked on by Maro Itoje, but Wasps can't take advantage as Danny Cipriani can't hold on to Nathan Hughes' quick offload.

There's a short break as a couple of players get treatment before this scrum, which is pretty much right in front of the posts.

Jeremy Guscott
Ex-England centre on BBC Radio 5 live sports extra

This is like an act in a play which has one actor speaking and someone keeps on jumping in.

Everything is Saracens - the defence, the attack, their game management.

Wasps are real hyenas - they are scavenging on bits and pieces.

Image source, Rex Features

It's a bit scrappy from the scrum, but Sarries still have the ball and are probing for any weakness in the Wasps defence.

Wasps can't keep hold of it at the breakdown, as Maro Itoje and Mako Vunipola power through to smuggle the ball away from Dai Young's side.

Sarries look to release Chris Wyles with a kick to the left, but Wasps make a meal of the line-out again, offering the hosts the put-in at the scrum.