Northampton emphatically took the East Midlands derby bragging rights as they ran in five tries to beat Leicester.

Matt Proctor's early brace on his debut was followed up by scores from Api Ratuniyarawa, Tom Collins and Fraser Dingwall in a free-flowing display.

Guy Thompson had crossed in the opening quarter to give Leicester the lead before Saints took charge.

A fourth victory in five games moves Northampton top above Bristol, who host London Irish on Sunday.

It had looked like being a disrupted build-up for Saints, who lost international trio Courtney Lawes, Dan Biggar and Owen Franks from their original starting line-up when all three failed late fitness tests.

But they showed no ill effects of playing without all that Test experience when one-time All Black centre Proctor was set free for the first try by Cobus Reinach's vision from the base of a scrum.

Leicester replied promisingly when back row Thompson had the power to crash over from an attacking line-out. But that was as good as it got for Tigers, who find themselves second from bottom with just one win in five this season.

Saints began to dominate as Proctor crossed once more at the end of a fine flowing move from right to left, and then Fiji lock Ratuniyarawa, who came in for the injured Lawes, went over before half-time.

Winger Collins then had a gift of a score to secure the try bonus point midway through the second half before replacement centre Dingwall was sent over with his first touch after Northampton pounced on an overthrown Leicester line-out.

As well as a fourth home Premiership win in a row for Saints, it was also a fourth successive win in all competitions against their old rivals, something they last achieved in 1973.

Northampton director of rugby Chris Boyd told BBC Radio Northampton:

"It's a bit of a trifecta for us really: We won and got five points so that's a pretty good start. We played well in more patches than we played badly and to get a win for our supporters against Leicester at home makes it a pretty good day.

"All credit to the supporters, the boys love it when it's like this, so we're happy.

"We lost 260 international caps before the start and I just thought people like Alex Moon, Ehren Painter and James Grayson came of age today.

"For James to come in late and run the ship basically at fly-half was a huge credit to him.

"When losing those players, the question in the changing room to the boys before the game was 'can we step up and do the job?' and I think the answer was emphatically yes."

Leicester head coach Geordan Murphy told BBC Radio Leicester:

"Incredibly disappointed is the way I would describe that performance and the way I feel. I'm just really gutted - we didn't really do anything we aspired to do in the week.

"I felt just before half-time at 17-10 down, we had a little opportunity in their territory to execute and to score.

"They stole the ball off the line-out and then went the length of the field to score and we find ourselves two scores down at the interval. The game's effectively done and dusted at that stage.

"When you start chasing the game in the second half as we had to against a quality side like Saints, they're going to hurt us.

"The manner of the defeat is sickening as this is a very special one this game, which means a lot to myself and a lot of the players."

Northampton Saints: Furbank; Collins, Proctor, Hutchinson, Naiyaravoro; Grayson, Reinach; Waller (co-capt), Haywood, Painter, Moon, Ratuniyarawa, Wood, Ludlam, Harrison (co-capt).

Replacements: Van Vuuren, Van Wyk, Hill, Coles, Gibson, Mitchell, Dingwall, Tuala.

Sin-bin: Moon (50).

Leicester Tigers: Worth; May, Tuilagi, Taute, Holmes; Ford, B Youngs; Genge, T Youngs (capt), Cole, Lavanini, Green, Wells, Thompson, Kalamafoni.

Replacements: Kerr, Gigena, Leatigaga, Lewis, Coghlan, White, Reid, Forsyth.

Referee: Matthew Carley (RFU).