Owen Farrell lands 19 points as Sarries beat Northampton 29-20
Earlier Wasps beat Exeter 25-24 with the final move of the game
Saracens and Wasps will now meet in the Champions Cup last four
5 English clubs made last eight - Leicester play on Sunday
Use 'Live Coverage' tab to select radio commentary
That's all from the land of the egg-shaped balls for today.
We'll be back on Sunday, when it's Leicester's turn to go for the Champions Cup semi-finals.
They host Stade Francais at 13:30 BST. See you then!
Saracens 29-20 Northampton
Saracens captain Brad Barritt has been speaking to BT Sport about a game of two very different halves for his side.
"A huge problem was our discipline in the first half. It was 9-1 in penalty count at half-time. Being on the back-foot played a big role," said the England back.
"But we're a team of guys who work hard for the team. Guys like Maro Itoje all stood up . We all stuck together and galvanized."
Saracens 29-20 Northampton
Paul Grayson
Former England fly-half on BBC Radio 5 live
"In the end you go back to the first half and the opportunity to put points on the board. Poor old Jamie Elliot made a mistake in not finishing off a try-scoring opportunity. Brad Barritt and Owen Farrell have been to the fore, Mario Itoje is just one of those players who always catches the eye."
Saracens 29-20 Northampton
It certainly wasn't vintage Saracens, but they've made it to the last four and maintain their unbeaten record in the competition.
It's Wasps up next in another all Premiership tie.
Saracens 29-20 Northampton
One more for the road!
It's too late for Northampton to hit, but they've decided they're going to walk away with the last points of the game.
Courtney Lawes pushes over and Stephen Myler converts. It's all over, though, and Sarries progress.
Saracens 29-13 Northampton
Image source, Getty ImagesThat's that, then. The comeback is almost complete.
Alex Goode's grubber kick gains ground for Sarries, and Northampton lose possession 10 metres from the try line.
The ball is collected by Chris Wyles and he dabs down. Owen Farrell does the business with the boot again.
Saracens 22-13 Northampton
Image source, Getty ImagesBilly Vunipola sweeps up from a Sarries scrum and they try to press forward towards the Saints 22.
Owen Farrell goes for a drop-goal, but it's weak and misses the posts. However, Sarries have already earned a penalty so they have another chance to extend their lead.
And Farrell nails it. Five minutes to go, and the hosts are pulling ahead.
Saracens 19-13 Northampton
JJ Hanrahan has come on for George Pisi as Northampton try to recover.
Ben Nutley is back on as well, after a head injury assessment.
Saracens 19-13 Northampton
Paul Grayson
Former England fly-half on BBC Radio 5 live
"Saracens are super dangerous in the second half. In the final 20 minutes fitness tells, strength in depth on the bench tells. A fantastic score from Chris Ashton, what we've seen over and over again from Saracens at their best, though they're not at their best today. Northampton will rue those missed opportunities in the first half."
Saracens 19-13 Northampton
Image source, Getty ImagesDid anyone order a swan dive?
Saracens finally get ahead as Chris Ashton bombs over in trademark style.
He darts forward on the diagonal and lands in the corner, after some brilliant handling by Alex Goode and Owen Farrell, who kicks the extras.
Ten minutes left. Can Sarries keep their 100% record in the competition?
Saracens 12-13 Northampton
Alex Goode floats a beautiful ball over the top to Chris Ashton, but the Sarries wing can't feed to Schalk Brits after Ken Pisi gets in the way.
The ball is kicked back into Sarries' half and they go on the march again, but play has been stopped as Ben Nutley is down injured.
Nutley is forced off and Michael Paterson replaces him.
Saracens 12-13 Northampton
Couple of replacements to report.
South Africa great Victor Matfield is on for Christian Day for Saints, while Campese Ma'afu is on for Alex Waller.
Sarries earn a penalty and Owen Farrell quickly pings the ball forward into touch. They're going for the maximum.
Saracens 12-13 Northampton
Paul Grayson
Former England fly-half on BBC Radio 5 live
Image source, Getty Images"This will go down to the wire."
Saracens 12-13 Northampton
Saracens smash Northampton in the scrum with a huge surge forward and they're going for the three-pointer.
Owen Farrell lines up his shot out on the left. Silence around Allianz Park, bar the whistle of the wind.
It's a one-point game again.
Saracens 9-13 Northampton
Image source, Rex FeaturesMaro Itoje, who was so impressive for England during the Six Nations, intercepts a Saints line-out and it stalls play.
And now Sarries are charging forward - Owen Farrell to Chris Ashton but arrrgh... Alex Goode can't get a handle on the pass. He looks very frustrated.
Saracens 9-13 Northampton
Image source, Getty ImagesSaracens flanker Will Fraser has been penalised for the umpteenth time. He's probably lucky to have avoided the sin-bin for multiple offences.
He's failed to release the tackle this time and it's a penalty to Saints. Stephen Myler is going to have a go in the swirling wind... it's over.
Northampton extend their narrow advantage.
Saracens 9-10 Northampton
Owen Farrell doesn't miss those ones. He slots with ease from close range, dead centre.
One point in it now.
Oh, and once again, Mako Vunipola has lost his contact lens. This happens in every game, I swear.
A replacement for Sarries as well, as Jackson Wray makes way for Michael Rhodes.
Image source, PASaracens 6-10 Northampton
Paul Grayson
Former England fly-half on BBC Radio 5 live
"We said before the game if this was going to be a contest Northampton would have to be at 100% and Saracens a bit below their best and that's the way it's been so far.
"Saracens lack accuracy in everything they do. There's been no flow or dynamism from their clearance work, it's been very un-Saracens-like."
Saracens 6-10 Northampton
Billy Vunipola tries to sneak through at the back of the scrum but the Saracens number eight is pole-axed to the floor by Teimana Harrison.
But now Sarries are gaining ground in attack. Brad Barritt powers forward, and they win a penalty bang in front of the posts.
Image source, Getty ImagesSaracens 6-10 Northampton
Image source, PABen Foden is forced off through injury so young Harry Mallinder is on for Saints at full-back.
He is, of course, son of director of rugby Jim and he's been impressive in his breakthrough season in the team.