Top work by Northampton's Courtney Lawes, though. He stops the red and black wave in its tracks and the collapsed maul gives Saints the put-in at the scrum. With less than 30 seconds to go until half-time, I'd imagine Northampton scrum-half Kahn Fotuali'i will be pretty keen to see out time here.

Tom Miszkowski:, external 100mph stuff so far, the wolf pack on top at the moment.

This is well worked by Saracens. Owen Farrell, recognising a lack of options both right and left, pokes the ball in behind and forces Northampton to cover and run it into touch. Another attacking line-out for Sarries, five metres out.

Nothing like a couple of collapsed scrums to dampen the spirits, eh? A couple of minutes have ticked by as we wait for the two packs to get it on. At long last, Saracens, who had the put-in, win the penalty. They kick for touch and have a line-out.

Paul Grayson
Former Northampton and England fly-half on BBC Radio 5 live

"It just looks like Northampton have got so more of a threat, once they have got the ball in hand."

Suddenly the noise levels have gone up a notch or two inside Twickenham. "The Saints are marching in" is echoing around this fabulous arena. Northampton edge ahead five minutes before half-time.

Ian Robertson
BBC rugby union correspondent

"Instead of taking the easy three points, Northampton opted for the line-out. Quick passing created the overlap. That was brilliant play."

Image source, Empics

And this time it pays off! The ball is switched from right to left and, thanks largely to a fabulous offload from centre Luther Burrell, full-back Ben Foden races over unchallenged. It's a fantastic team try, on what was Northampton's first visit to the Saracens 22. Stephen Myler converts, and Saints lead.

The first drive from the line-out is halted illegally by Steve Borthwick, and it's another penalty. To touch we go again...

BBC Radio Northampton's Graham McKechnie: "That was a shocking professional foul by Alex Goode. He knew exactly what he was doing. That has to be a yellow card."

Wow, the highlight of the final so far! Northampton's Samoan winger Ken Pisi breaks three or four tackles to run the ball from his own 10-metre line to within touching distance of the Saracens try-line. They win a penalty after Alex Goode steps offside to prevent Saints moving the ball, and Stephen Myler kicks for touch.

Here comes Owen Farrell, breaking the Northampton defensive line. But one forward pass later and it all breaks down.

Paul Grayson
Former Northampton and England fly-half on BBC Radio 5 live

"Northampton won't want to spend any more time in this position deep in their own half because any more mistakes will be three points for Saracens."

Now the ball is worked dangerously forward down the line and Saints' Ken Pisi can only run, or slide, it into touch. Saracens have the line-out around 10 metres from the line, but the rolling maul breaks down to Northampton's advantage and it'll be their put-in at the scrum this time.

It all seems a little subdued around Twickenham at the moment. Sarries will be very happy to be six points ahead, but there's not been a huge amount between the sides. Now here's the first scrum of the afternoon - Neil de Kock has the put in for Saracens and it's well executed.

Brian Moore
Former Harlequins and England hooker on BBC Radio 5 live

"Not clever from Northampton. The sides are very even but Northampton have given away three penalties from a kickable distance. They started off well and got a few coherent phases but now they've progressed to this kicking game, which they're not winning. They're getting no momentum."

These penalties sure are mounting up, aren't they? Now Sam Dickinson is caught offside and it's another chance for Owen Farrell. This is the toughest and furthest of his chances so far, and he drags it wide.

Another nice mini-break by Marcelo Bosch is halted by Ken Pisi. Now, Owen Farrell switches the ball across for Saracens and David Strettle again takes the ball brilliantly out of the air, before then stepping into touch. Unlucky.

And Farrell again makes no mistake, with a kick from a slightly tighter angle than his last. Fancy another stat? Of course you do. Saracens have won all 13 Premiership games their leading fly-half has played in this season. Ominous for Saints.

The Saints defence is holding firm though. Now, another long Saracens kick forward is brilliantly gathered by David Strettle above Ken Pisi. How about that for a take by the Sarries winger - and as a result there'll be another chance for Owen Farrell after Northampton are penalised for entering the ruck at the side.