Chipstead's players and manager were left devastated after AFC Wimbledon's late, late show denied them a famous victory in the Surrey Senior Cup quarter-final at High Road on Tuesday night.

Two goals by Scott Simpson had given Chipstead what looked like a commanding 3-1 lead minutes after half-time.

But having taken off Jon Main and scorer Danny Kedwell, who have 34 goals between them in the Blue Square Premier this season, at the interval, the Dons went on to snatch victory.

They scored via a disputed penalty and then levelled on 89 minutes, before snatching victory in the third minute of injury time to earn a semi-final against Walton & Hersham or Godalming Town.

Chipstead boss Mark Tompkins, said: "We should have won. How many chances did we have? We had two one on ones, Sean Rivers had a free header and Ray Freeman had a great chance but wellied it. We should have been out of sight."

Tompkins had long insisted the game was one to enjoy, with no pressure on his Ryman South team four divisions below their visitors.

"I said for us it would be a game to enjoy. We wanted a good performance.

"We knew they would be a strong side, but after the game we're thinking we've thrown that away.

"It just shows how far we have come, from losing 6-0 against Dartford in the FA Cup early in the season to playing AFC Wimbledon and coming off disappointed that we haven't won."

He praised Simpson and Rivers, who scored Chipstead's first to level on 18 minutes, for the way they worked the line.

Tompkins was left frustrated by the penalty for a shirt pull which brought the game back to 3-2, which looked a harsh decision from Kingston referee Darren Sheldrake. "I don't think it was a penalty and he said afterwards maybe I might have got it wrong – but I don't want to hear that now, do I?"

In the first half, however, Wimbledon thought they not only had a case for handball on Chipstead's line but that the ball was actually over the line. "I heard it might be," reflected Tompkins, who will be as keen to see the video the Dons made via a man filming from on top of the clubhouse as many Wimbledon fans.

Tompkins also had much praise for Adam Peck, the keeper who made several fine saves in the second half as Chipstead's rearguard made a valiant attempt to keep out AFC Wimbledon's lively second half strikers Luke Moore and Nathan Elder.

The night looked ominous for Chipstead after Kedwell, who had several chances, headed in the opener after 11 minutes. Freeman, the left winger, spent much of the first half defending, but when Chipstead broke they made the most of it.

From three shots - one off target - they scored twice, the first when Rivers juggled the ball past Seb Brown - recently unbeaten in the Blue Square Premier for 600 consecutive minutes - to equalise on 18 minutes. "I thought a defender was going to come up behind me and take the ball, but there was nobody there," said a stunned Rivers afterwards.

The Dons failed to make the most of several free-kicks before Simpson, after Nicky White's pass, scored in first-half injury time, nipping in as the defence went missing, netting with his second touch.

Two minutes after half-time, Simpson picked up the ball on the halfway line on the left, sprinted forward with it and slid the ball past Brown. Simpson didn't even celebrate. "The game wasn't over," he gave as the explanation.

"We had the chances and we knew we could have finished it off – we're gutted," the striker added.

"They were over-running us by the end," he admitted. "We hit them on the break well and it's disappointing.

"With the squad we've got now, if we had started with that at the beginning of the season we would be pressing near the top of the league," said Simpson, who returned to High Road a few days before the campaign began.

Peck, a teenager voted man of the match, started a tremendous half by tipping away an Elder shot at full stretch, then found a ricocheting ball at his feet. It could have gone through his legs, but he got some luck as it stopped and he picked it up.

Peck made another full-stretch save with 15 minutes left, but could do nothing about former Brentford midfielder Poole's penalty, nor the header from which Gregory headed in the equaliser from the disputed free-kick.

The man doing AFC Wimbledon fans' radio told his listeners he feared frost bite as extra-time loomed, but it was not to be.

A valiant defensive display from Louis Hollingsworth and James Russell – and midfielder Allan Matthews – was finally, cruelly, undone with a piece of jinking magic from Poole, who curled a delightful shot past Peck at the end of his run.

Tompkins, rightly, could not pick out individual performances. The whole team can live off the credit for this performance for some time.

Chipstead: Peck, Bedford, Hollingsworth, Russell, Thompson, White (Grizzle), Matthews, Smith (Moody), Simpson, Rivers, Freeman. Unused subs: AJ Morrison, Tompkins, Leigh (gk).