Reigning champions Leicester reached the English Premiership final after an 11-3 semi-final win over Northampton on Saturday denied the European Cup finalists a possible double.

The Tigers were fortunate to finish with 15 men after teenage centre Manu Tuilagi landed a crunching right hook on England winger Chris Ashton.

Both players were yellow-carded for their roles in the incident, one of several flashpoints in a fiery East Midlands derby.

Northampton coach Jim Mallinder, who must raise his team's spirits for next weekend's European Cup final against Irish province Leinster in Cardiff, questioned how the 19-year-old Tuilagi escaped a red card from World Cup referee Wayne Barnes, acting on the advice of touch judge Robin Goodliffe.

"First of all, you can't have players taking players out, and you can't be hitting players directly to the head, punching," Mallinder said.

"Chris Ashton did go over and give him a push, but you cannot react with three punches to the head without a red card.

"When you come to places like this, you don't get the 50-50s.

"I think the referee did go to his assistant. All I know is I have seen it, and to me, it is a clear red card. What did Ashton get a yellow card for - pushing?"

A late try from Alesana Tuilagi, Manu's older brother, and two Toby Flood penalties saw Leicester into a May 28 Twickenham final against either Saracens or Gloucester, who meet on Sunday.

But Manu Tuilagi could well miss the showpiece match, which will see Leicester bidding for a second hat-trick of Premiership titles, if the citing commissioner decides his punch is worthy of a ban.

Leicester coach Richard Cockerill insisted he didn't see the Tuilagi incident and was annoyed by suggestions it had been a turning-point.

"I was watching the ball, but the assistant referee clearly saw it and deemed it as a yellow card offence. I haven't seen the replays of it," Cockerill said.

"It was a good performance against a really good side. Let's talk about that shall we?," the former England hooker added.

"Let's talk about how we controlled the game, let's talk about Alesana's try, let's talk about the scrum contest, not all the crap you boys (the press) want to talk about and make headlines out of."

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