Saracens have their bonus point after 33 minutes, Mano Vunipola grabbing his second try of the match to put his team 31-0 up.

Not quite so one-sided between Harlequins and Newcastle, however, where Quins are still edging it 3-0.

Image source, Getty Images

Oh dear, oh dear Dylan Hartley. What have you done? The replays show that the Northampton and England hooker has thrown an elbow into the face of Leicester centre Matt Smith, who crashes to the floor. Hartley was being held, but you just can't do that. Referee JP Doyle brandishes the red card and, just like the 2013 Premiership final between these sides, Hartley is sent off.

Chris Osborne
BBC Sport at Franklin's Gardens

"I was about to say it was a quiet start, until that mass brawl broke out in front of us.

"Salesi Ma'afu laid out Tom Youngs with a punch last time the teams met remember. And there is a sense that this is very close to becoming a fight rather than a rugby match."

These East Midlands derbies are always feisty affairs and there's an altercation between a number of players from both sides as Leicester turn the ball over at the ruck just inside the Saints' half. Tigers move the ball well and are stopped near the line. But more fighting breaks out and referee JP Doyle goes upstairs to the Television Match Official to find out just what has gone on.

That's a big push from Leicester at the scrum! It goes down and referee JP Doyle hands the Tigers a penalty. It's a difficult one, on the Saints' 10-metre line and five metres in from touch. Owen Williams strikes it well enough but it's off target and drifts to the left of the posts. We await our first points.

Play swings this way and that as both sides kick for territory. But Tigers scrum-half Ben Youngs puts a lovely little chip into touch inside the Northampton 22 and there will be some pressure on this line-out. Courtney Lawes rises highest to claim the ball and Saints are then awarded a free-kick to eliminate any immediate threat of danger.

Saracens have been absolutely rampant in the opening 20 minutes against London Welsh and lead 24-0, with Brett Sharman and George Kruis adding to Mako Vunipola's earlier try. They could have a bonus point wrapped up before half-time at this rate.

At The Stoop, Newcastle Falcons are pressing against Harlequins but still trail 3-0.

It all goes wrong for Saints at the scrum and Ben Youngs is able to clear for the visitors. Tigers flanker Tom Croft then steals the ball at the Northampton line-out and all of a sudden we're in the Northampton 22. Leicester's pressure is short-lived, though, as a penalty allows Stephen Myler to take play back into the Tigers half.

A quick tap penalty in midfield has Northampton racing forward and only a brilliant tackle from Owen Williams prevents George North from scoring. Tigers turn the ball over at the ruck but knock-on in the process and Saints will have a scrum five metres out.

Leicester have the first line-out of the game just inside the Saints' half but they are penalised for obstruction and Northampton have the penalty and the chance to kick for territory. But Stephen Myler misses touch with his kick and Tigers have the chance to clear their lines.

Quins are 3-0 ahead against Newcastle at The Stoop thanks to an early penalty from Tim Swiel.

Saracens, meanwhile, are now 10-0 up on bottom-side London Welsh after a kick from England fly-half Owen Farrell. Sounds like a fairly ominous start for Justin Burnell's side.

Like last May's Premiership final, JP Doyle is our referee. He blows his whistle and Leicester's Owen Williams gets us under way.

Jeremy Guscott
Former Bath & England centre

"You look at the Northampton pack and it is humongous. And the quality that it has is difficult to match for any side - that is why they are the best team in the Premiership and are the current champions.

"They are going well and just have that extra sprinkle of stardust at the moment, so I expect them to win."

You can read Jeremy's BBC Sport column on Premiership derby day by clicking here.

Saracens have the lead at Allianz Park as prop Mako Vunipola scores after a dominant driving maul from the hosts and Owen Farrell makes no mistake with the conversion.

Northampton Saints: Wilson; K. Pisi, Stephenson, Burrell, North; Myler, Fotuali'i; A Waller, Hartley (capt), Ma'afu; Lawes, Day; Clark, Wood, Manoa.

Replacements: Haywood, E. Waller, Denman, Dickinson, Dowson, Dickson, Elliott, Foden.

Leicester Tigers: Tait; Scully, Smith, Allen, Goneva; Williams, B Youngs (capt); Ayerz, T Youngs, Cole, Kitchener, Parling; Croft, Salvi, Crane.

Replacements: Ghiraldini, Rizzo, Balmain, De Chaves, Barbieri, Harrison, Burns, Benjamin.

Image source, Getty Images

England centre Luther Burrell returns to a Northampton side, which also sees Alex Waller, Christian Day and Samu Manoa come into the pack.

England hooker Tom Youngs and flanker Tom Croft are back for Leicester Tigers.

Youngs makes his second Premiership start since September after recovering from a shoulder injury, while Croft starts for just the second time this season after struggling with a knee injury.

Graham Kitchener moves into the pack to replace dual-code international Brad Thorn (calf), while Marcos Ayerza will make his 200th Tigers appearance.

Our two 15:00 GMT kick-offs between Harlequins and Newcastle, and Saracens and London Welsh, are now both under way.

We'll keep you posted with what's going on in those matches as the afternoon goes on.

Chris Osborne
BBC Sport at Franklin's Gardens

Image source, Chris Osborne

"Not long now. Saints and Tigers go through their warm-ups on a bitingly cold day. It's an afternoon for wearing fingerless gloves, something which I'll be asking Santa to get me this year."

Image source, Getty Images

Leicester might have endured a difficult start to the Premiership campaign, losing three successive games in September and October.

But they will step out at Franklin's Gardens on the back of four games unbeaten in the league and having beaten European champions Toulon at Welford Road in the Champions Cup.

"We are one loss from seven games and played a very good Toulon side back-to-back and beat them once," Tigers boss Richard Cockerill told BBC Radio Leicester.

"We know we have played with a huge intensity and physicality the last couple of weeks and we have to take that to Franklin's Gardens, then take it to Sale, then Bath at home and Harlequins away."

Image source, Getty Images

Northampton may have won that last meeting but it's Leicester who have dominated this fixture.

It was Saints' first victory in 11 attempts against their East Midlands rivals, with Northampton going on to beat Saracens to win the Premiership title for the first time.

But Tigers have eight titles to their name and Saints full-back Ben Foden says his side are desperate to get the upper hand.

"We've always been second fiddle," he told BBC Radio Northampton. "This squad of players and this club are at the point where we want to compete with them and hopefully take that title away from them.

"We did that by beating them in a semi-final last year and then winning the Premiership, but we need to back it up with another big performance."