Leaders Leicester earned their biggest-ever win at Northampton to maintain their perfect Premiership start.

Alex Mitchell and Alex Waller scored for Saints after the break.

A Ford drop goal and two penalties kept Tigers clear before tries from Jack van Poortvliet and Kini Murimurivalu.

Skosan scored a second try at the end of the half, in front of a sellout Franklin's Gardens, when he went over with three minutes left before Van Poortvliet got his second with 30 seconds to go.

Northampton remain fourth in the table while their East Midlands rivals Leicester are nine points clear at the top, with second-placed Harlequins having two games in hand.

Tigers' first-half ruthlessness was matched by Northampton's mistakes as Ford's early penalty was added to by Nadolo's opener, the Fiji international going over on the left wing after a looping Dan Kelly pass.

Kelly provided the second as he left four Saints defenders in his wake with a tricky run to set up Van Wyk's 19th-minute try, before Nadolo sprinted in from 40 metres for the third try when Alex Mitchell misjudged a high kick.

A period of intense pressure in the right corner caused the fourth try as a close-range lineout saw Argentina captain Montoya mauled over, before Skosan scored in the left corner for Saints having seen Rory Hutchinson miss the chance to find him with an overlap two minutes earlier.

Leicester's discipline deserted them shortly after half time as scrum-half Richard Wigglesworth was yellow-carded for a head-on-head collision, and Cobus Wiese was sin-binned for a no-arms challenge in the build-up to Mitchell's try shortly after.

Against 13 men and with a partisan home crowd behind them Saints rallied as Mitchell was held up over the Tigers line.

But Tigers' survived as the impressive Ford calmed his side's nerves with a 41-metre drop goal after a Saints drop out 15 minutes into second half, although two minutes later Waller bundled his way over on the left to cut the gap to 11 points.

Ford - whose all-round kicking game gave Leicester a great base to play from throughout the 80 minutes - landed two more penalties before Van Poortvliet blocked Rory Hutchinson's kick and went over with 15 minutes to go, and Murimurivalu smashed his way over five minutes later.

Skosan found himself on the end of a Grayson cross-field kick to go in unchallenged, but there was still time for Steve Borthwick's men to score again as young scrum-half Van Poortvliet intercepted a pass and galloped over.

Northampton director of rugby Chris Boyd told BBC Radio Northampton:

"We knew what was coming but we didn't deal with it.

"They went down to 14 and then 13, we had five opportunities and took two of them.

"If we could have taken another couple of those and made it an even ball game I think it might have been a different script, but as it turned out our poor performance in the first 30 minutes was too big a mountain to climb.

"We didn't win the collisions and we didn't win the balls in the air, so if you don't win those then all you're doing is inviting a guy like George Ford, who I thought was good, to control games."

Leicester head coach Steve Borthwick told BBC Radio Leicester:

"I thought their attitude was outstanding, I thought their work rate was outstanding, their effort was brilliant.

"What I also say is how do we get better? Because there's no point in just saying we won't bother and there's plenty to get better about.

"The last five minutes of the first half we gave them a try and that made the start of the second half difficult and we made it even more difficult by going down to 13 men.

"Again I'll praise the players, the guts and the spirit they showed when they were down to 13 men, but we can't be in that situation."

Northampton: Hutchinson; Skosan, Proctor, Dingwall, Collins; Biggar, Mitchell; Waller (capt), Matavesi, Painter, Ribbans, Ratuniyarawa, Wood, Harrison, Augustus.

Replacements: Haywood, Auterac, Hill, Moon, Coles, Lomani, Grayson, Litchfield.

Leicester: Burns; Potter, Moroni, Kelly, Nadolo; Ford (capt), Wigglesworth; Van Wyk, Montoya, Cole, Wells, Snyman, Chessum, Van Staden, Wiese

Replacements: Cowan-Dickie, Leatigaga, Heyes, Green, Reffell, Van Poortvliet, Hegarty, Murimurivalu.

Referee: Tom Foley (RFU).