Premiership champions Leicester fought back to beat Northampton in a compelling 250th East Midlands derby.

Alex Coles and Guy Porter traded tries as Saints took a slender 21-17 lead.

The hosts had two men in the sinbin when former Saint Chris Ashton edged Tigers ahead before George Martin's try and Steward's late brace sealed it.

An extraordinary finale saw a staggering late collapse from Saints who had three men yellow carded in eight minutes before shipping 24 unanswered points to let slip a 21-17 lead in the last 11 minutes.

Freddie Burns' penalty gave Tigers a sixth-minute lead, but the hosts dominated territory in the opening half-hour, with Dan Biggar seeing a try ruled out for a forward pass.

But Saints did soon have the lead when a swift attack saw Freeman send Mitchell away to touch down under the posts and within a minute of Biggar's conversion, George Furbank broke the line and had Freeman in support to run in Northampton's second.

Trailing 14-3 within 17 minutes, Tigers had to wait almost half-an-hour before their first attacking threat, with Biggar making a try-saving tackle to deny Jimmy Gopperth in the corner.

Leicester seized the momentum, forcing a string of penalties before Burns spun a long pass out wide for Steward to stroll in unopposed.

Fine work from Lewis Ludlam allowed Coles to finish another impressive Saints move four minutes after the break, but Tigers hit back within two minutes when Porter powered over following a burst from winger Nemani Nadolo.

Saints number eight Juarno Augustus was shown a yellow card after 64 minutes, with prop Emmanuel Iyogun sin-binned four minutes later as the Saints penalty count continued to climb in the face of incessant pressure.

Leicester had trailed since the 10th minute, but edged 22-21 ahead with 11 minutes left when Ashton finished in the corner against his former employers, just moments after coming off the bench.

Martin dived in for Tigers and things grew worse for Northampton who had to play with just 12 men for two minutes when Mitchell became the third man sent to a crowded sin-bin.

The champions showed their ruthless side, capping an immense second-half display with a late brace for Steward who marked his first appearance of the season in some style.

Northampton Saints director or rugby Phil Dowson:

"When you put a side under pressure, they'll give penalties away and if you give enough penalties away, you get yellow cards.

"We start doing things you wouldn't necessarily do, so pressure will lead to ill-discipline, ill-discipline will lead to punishment and I think I saw that today.

"We were under a ton of pressure at the set-piece. All those different things have an impact and that leads to that situation.

"I don't think there was anything wrong with our discipline when we were not under pressure, people will make errors when they're under a lot of heat."

Leicester Tigers head coach Steve Borthwick told BBC Radio Leicester:

"Northampton are such a great attacking force, the speed at which they move the ball. The way they played was superb, the way they moved the ball and stretched our defence.

"We hung in there and were fortunate enough to come away with the win in the end.

"We altered a couple of things, made a couple of tweaks and did really well out there. I thought the players who came on and finished the game were absolutely outstanding."

On Freddie Steward: "The character that he is, the personality that he is, the energy he brings to the environment, the desire he brings, he deserves immense credit for everything he achieves."

Northampton: Furbank; Freeman, Dingwall, Hutchinson, Proctor; Biggar, Mitchell; Iyogun, Matavesi, Petch; Salakaia-Loto, Coles, Lawes, Ludlam (c), Augustus.

Replacements: Haywood, Waller, Hill, Moon, Scott-Young, James, Grayson, Collins.

Sin-bin: Augustus (64), Iyogun (68), Mitchell (72).

Leicester: Steward; Potter, Porter, Gopperth, Nadolo; Burns, van Poortvliet; Cronin, Clare, Cole; Chessum, Green, Martin, Reffell, Liebenberg (c).

Replacements: Taufete'e, van Wyk, Heyes, Wells, Cracknell, Youngs, Cokanasiga, Ashton.

Referee: Karl Dixon (RFU).