Cheltenham Town were eliminated from the LDV Vans Trophy on sudden death penalties after a marathon game at the Abbey Stadium.
After 120 minutes of football and seven penalties each, young Martin Devaney was the unlucky player whose spot kick hit the post and sent Cambridge United through to the Southern Area semi-final.
Neil Grayson, Lee Howells, Jamie Victory and Mark Yates all scored their penalties while Julian Alsop and Hugh McAuley had theirs saved by goalkeeper Lionel Perez.
Paul Wanless, Andy Duncan, Tom Youngs, Ian Ashbee and Daniel Chillingworth scored for United. Alex Revell had his spot kick saved by Steve Book and Shane Tudor hit the crossbar.
The defeat was very harsh on Cheltenham who had dominated long periods of the game against Second Division United and looked the only side likely to win during the 30 minutes of extra time.
They won 17 corners to United's four and had easily the lion's share of goal scoring opportunities.
The match was played in a rather subdued atmosphere, the crowd falling well below Cambridge's average of around 3,500, and the players seemed to respond in kind by serving up an error-strewn first half with little pattern or cohesion.
Lee Williams and Julian Alsop both tried their luck with long-range shots as Cheltenham made a confident opening, but they were rocked back by a goal after 19 minutes from Cambridge's French starlet Armand One.
The 18-year-old, who had scored six goals in six games before this match, turned sharply onto a pass from Dave Kitson on the edge of the area.
The speed of his turn foxed Cheltenham centre-backs Michael Duff and Chris Banks, who left a big gap for him to run into and plant a low drive beyond Steve Book from 12 yards.
Aside from the goal, first half chances were few and far between.
Book slid out bravely to save at the feet of Colin Alcide and Lee Howells had a shot held by United's unconventional French goalkeeper Lionel Perez.
Russell Milton was withdrawn after 31 minutes and replaced by Hugh McAuley, it was not immediately obvious whether Milton had picked up an injury or whether the move was tactical, but McAuley was soon into the action when his pass gave Neil Howarth the chance for a shot that flew wide.
McAuley took a free-kick from the edge of the area that was comfortably held by Perez but both teams were being far too generous with possession, giving the ball away with almost wreckless abandon.
United midfielder Tom Youngs headed just wide from an Alcide cross shortly before half-time, and the only incident in the first 15 minutes of the second half was a Cheltenham substitution - such was the poverty of goalmouth action.
This time it was Lee Williams who left the fray after going down with a leg injury six minutes after the break.
Neil Grayson replaced him and the Robins switched to three up front, the move seeming to inject an extra spark into the Cheltenham team almost immediately. Cambridge found themselves under concerted pressure for the first time in the match, and the result was an equalising goal in the 63rd minute.
Mark Yates foraged into the penalty area down the right-hand side and held off a defender's challenge before pulling the ball back for Tony Naylor to strike from eight yards.
Cambridge immediately made a double substitution of their own, sending on Richard Prokas and Daniel Chillingworth for the front two, Kitson and One.
Alcide sent their first chance of the second half over the bar with around 20 minutes left, but Cheltenham went close to grabbing victory with two chances in the closing minutes.
Grayson worked himself the chance for a shot, which Perez beat away when he could have caught it, and Naylor almost won it for Cheltenham in the 89th minute.
McAuley's corner was flicked on by Grayson and Naylor's stooping header was touched against the post by Perez.
And so we went into golden goal extra-time. Jamie Victory, who had enjoyed another fine game for Cheltenham, sent a diving header inches wide from a Lee Howells cross Perez saved with his legs from Naylor as the Robins piled forward in search of a goal.
Naylor beat three players in a skilful solo run that took him past three players but he was unable to get a shot on target, Grayson and Howells both went close and McAuley's dangerous cross went begging during a first 15 minutes of almost complete one-way traffic.
Cambridge created only one chance before the turnaround, Chillingworth heading a cross from substitute Alex Revell wide.
Martin Devaney replaced Naylor with seven minutes and he forced Perez to make a spectacular save with virtually his first touch.
Victory then went close with a header as Cheltenham forced four corners in quick succession but somehow the United defence held out to take the game to penalties.
CAMBRIDGE UNITED: Perez; Warner, Duncan, Angus, Ashbee; Youngs, Tudor, Wanless, Alcide (Revell 104); One (Chillingworth 65), Kitson (Prokas 65). Other subs: Walling, Marshall.
CHELTENHAM TOWN: Book; Howarth, M. Duff, Banks, Victory; Williams (Grayson 51), Yates, Howells, Milton (McAuley 31); Alsop, Naylor (Devaney 112). Other subs: Brough, Muggleton.
REFEREE: R.J. Olivier (West Midlands)
ATTENDANCE: 1,511