Sunderland manager Sam Allardyce has admitted that his side are under "extreme pressure" following their 2-0 home defeat at the hands of Leicester City this afternoon.

The Black Cats stifled the Premier League leaders for much of the match, but were eventually undone by Jamie Vardy in the 66th minute before the England international added a second in stoppage time.

Sunderland struggled to test Kasper Schmeichel for the most part, but squandered a glorious chance to equalise with just eight minutes remaining when Jack Rodwell fired over the crossbar from close range.

"We were nervous today because of how big the game is. It's a legacy of not picking up the points when we should have done. That caused us to do the wrong things to try and get back in the game. We didn't pass it anywhere near as well as we can. I think that was the main problem, not Leicester," Allardyce told Sky Sports News.

"We kept losing the ball in good areas, it was nothing like the passing game we showed against West Brom. We switched off once and our defence allows Jamie Vardy to do what is his major strength. He does what every top goalscorer does and scores it. The disappointing thing was how we reacted to that.

"I thought we were very poor after that. Jack Rodwell should have scored, you can't get a better chance than that and it would have put it at 1-1, then in the final five you have to throw caution to the wind and they created some chances."

Sunderland take on Norwich City in a relegation crunch match next weekend, and Allardyce acknowledged that today's result has piled more pressure on his side to beat the Canaries.

"Norwich was always going to be big. There would be less pressure if we had won but today was always going to be difficult to win. We are under extreme pressure that we have to make sure we handle," he added.

The defeat leaves Sunderland four points adrift of safety, although they do still have a game in hand over 17th-placed Norwich.