Harry Redknapp admitted Charlie Austin is his Rolls Royce after the striker fired Queens Park Rangers to Wembley.

Revved-up Austin took his tally for the season to 20 goals with a brace, including an extra-time winner, as Rangers came from behind to sink Wigan 2-1 in a dramatic Championship play-off semi-final.

Rangers were in the automatic promotion race until Austin suffered a shoulder injury in January which kept him out for three months.

By the time he returned Redknapp's side had slipped right off the pace, but the former Burnley frontman has kept their promotion dream alive by booking a winner-takes all showdown with Derby at the end of the month.

"He's scored in almost every game since he's come back, he's so important to us," said Hoops boss Redknapp.

"It's a great night for the fans and they've got a Wembley trip to look forward to which is great."

Yet Wigan, held 0-0 in the first leg, had stunned the hosts by taking an early lead.

James Perch darted in front of Rangers skipper Clint Hill to get to James McClean's centre first and poke the ball home.

Clearly a man for the big occasion, the goal was only Perch's second of the season - the other being the winner against Manchester City in the FA Cup which did send Wigan to Wembley.

But Rangers levelled in the 72nd minute when Junior Hoilett was fouled just inside the area by Gary Caldwell and Austin tucked in the penalty.

And Austin won it six minutes into extra time when he raced onto substitute Bobby Zamora's chip and fired home.

"We wanted to put pressure on them but we couldn't, so we went two up front and I thought the game changed then," added Redknapp.

"I felt from them on we were the better team, we really went for it. Bobby Zamora came on and did magnificently, we showed a lot of character, it was a great performance.

"We've got a great game to look forward to now with Derby, they are a good side so it will be an interesting game.

"We can get excited tonight but then we'll come down to earth."

Wigan had further chances to extend their lead but McClean opted to dive rather than round keeper Rob Green and was deservedly booked, while the forward hit a post after the break.

And Rangers' hearts were in their mouths in stoppage time when Rob Kiernan's shot was deflected inches wide.

So Wigan's season is finally over after a marathon 61 matches, but manager Uwe Rosler denied a gruelling second leg at Loftus Road was one game too many.

"It's one game too less," he smiled.

"We gave it our all. The players squeezed out every drop they have. We started well and we got the goal but they got the momentum and overpowered us.

"But before they scored we had some good chances, and in extra time we were unfortunate not to equalise."