Image source, Getty Images

It actually turns out to be a pretty useful line-out, but Harlequins defend their line wonderfully. There's another Saints penalty though and once again they go for the line-out.

Harlequins fully deserve to be in this, but do they have enough to topple the champions?

Their ill discipline at scrum time costs them again and Saints can regroup. Oddly, they go for the corner rather than the posts.

A bit of controversy in the build up to that try. Tom Stephenson gets Jack Clifford off the ground and plants him on the floor.

The TV official reckons it's not dangerous though. It's a close call if you ask me.

Finally Harlequins get what they're looking for. After Tim Swiel's near miss, Quins recycle and get their rewards for their persistent banging on the door with Jack Clifford creeping over.

Swiel converts.

So, so close. Tim Swiel may regret cutting his fingernails this morning, as he is millimetres from stretching the ball down over the line.

It's a first bit of rugby since September for Alex Corbisiero, who steps into the front row. There's also a change at scrum-half for Saints, with Kahn Fotuali'i coming on for Lee Dickson.

Don't get too excited Quins fans. Stephen Myler has one of the most reliable boots in the business and he snaffles a Saints penalty to put us back where we were moments ago.

Andrew Priestley:, external This is daylight robbery at Twickenham! Clinical from Northampton Saints, but that's why they're the reigning Champions! #bbcrugby

Tim Swiel needed that. He's been a bit wobbly off the tee today and even this one isn't convincing. It's between the posts though and the South African has his side's first points of the half.

Quins go through the phases but don't really make the ground they need. Tim Swiel has a chance from the boot though as Saints concede at the breakdown.

A few seconds of madness. Danny Care looks like a genius with a tap penalty. He then looks a fool as he chucks it straight to Ken Pisi.

Pisi looks to be away, but a remarkable tackle by Tim Swiel, with his fingertips, puts the wing on the turf.

You fancy that Saints will miss Samu Manoa a little bit next season.

The American number eight is off to Toulon in the summer and he has pretty much been the difference today. A big loss for Northampton and the Premiership.

Nightmare for Quins. Tim Swiel's kick is charged down by a bustling Samu Manoa. He beats Matt Hooper to the loose ball and pops it up to George North.

North doesn't tend to miss these types of chances, and he crosses with ease.

Stephen Myler lands the conversion, and all of Quins' good ground work in the first half could well be for nothing.

It looks relatively straightforward. But Tim Swiel puts it wide.

As it stands, Saints are back at the top of the Premiership. They have three minutes left to play with Salesi Ma'afu in the sin bin.

Tim Swiel starts the second half and even though Saints retrieve it well, they concede a penalty.

Image source, Getty Images

Harlequins didn't just dominate the first half in terms of possession.

They made 82 carries compared to Saints' 19, and made 224 metres against Saints' 53.

Plus, Northampton had to make 72 tackles, Quins made just 19.

But the champions lead by five points - smash and grab anyone?

John McEnerney:, external #bbcrugby The Saints more like The Sinners, good to see Alex C back he's a beast & showed it big time in Oz with the Lions!

What do you make of that first half? Are Saints looking like champions? Will Quins rue some missed opportunities?

Tweet us your thoughts using #bbcrugby.

All the numbers, apart from the key ones, suggest Harlequins should be in a pretty comfortable position right about now.

They had more than 70% of the possession in that first half - which is a massive chunk by anyone's standard.

But champions find a way to win I guess, and Saints, who have been uninspiring, have eked out everything they possibly could from that first half.

Brian Moore
Former England hooker on BBC Radio 5 live

"Northampton have left untouched the attacking potential of both Pisi's, Ben Foden and George North - and I hope for their fans that they get more involved because Saints have so much more to give."