City Under-21s suffered a 2-1 defeat to West Ham United in the third round of the Under-21 Premier League Cup at Ashton Gate.
Goals from Danny Whitehead and Elliot Lee in the space of nine second-half minutes were enough to secure the Hammers’ progression.
Wes Burns' 76th minute penalty gave the Robins hope of a comeback, but Mitch Brundle and Marley Bishop both missed opportunities in the closing stages to force the tie into extra time.
Lee carved out the first opportunity of the game when he made himself a yard of space on the edge of the box but saw his powerful shot tipped over by Dave Richards.
The on loan Cardiff City goalkeeper was called into action again moments later when he got down well to his right to turn Paul McCallum’s volley around the post after the striker latched on to Kieran Bywater’s cross.
City’s first chance came via Lewis Hall’s curling free kick from 25 yards which Sam Howes unconvincingly tipped over the crossbar.
The visitors were in control and could have gone ahead again through Lee but his ambitious volley from distance dipped just too late.
Mark O’Connor’s side struggled to keep up with the pace of the West Ham forwards with both Jordan Wynter and Pierce Mitchell going into the referee’s book for rash challenges on Whitehead and Matthias Fanimo respectively.
The Hammers continued the same high tempo in the second period and McCallum thought he put his team in front only for his header to bounce narrowly wide from Bywater’s corner.
City responded well to that scare and Brundle nearly put the Robins ahead but was unable to find either corner with his stabbed effort that went straight into the hands of Howes.
Kevin Krans squandered City’s best chance of the afternoon when he blazed his volley into the Atyeo Stand following Brundle’s knockdown from Joe Morrell’s deep free kick.
Moments later the deadlock was finally broken when Whitehead raced clear of the City defence before finding the far corner with a great finish past Richards.
A fantastic last-ditch tackle from Brundle then denied Fanimo from eight yards after a neat passing move by the visitors.
Fanimo was then heavily involved in the crucial second goal when his spectacular first-time cross found Lee at the back post, who converted the simplest of headers to double his side’s lead.
The Robins replied instantly from the penalty spot when Frazer Shaw made a reckless challenge on Burns and the referee was forced to point to the spot.
The Welsh Under-21 international dusted himself off to fire into the bottom left corner, sending Howes the wrong way in the process.
Brundle had the chance to send the tie to extra time but fired the wrong side of the post after Hall’s free kick deflected into his path.
Bishop nearly levelled seconds from the end, but, after racing clear of Leo Chambers, the forward shot straight at Howes, leaving the City youngsters to reflect on what might have been.
City Under-21s: Richards; Mitchell, Brundle, Batten, Hall; Mafuta, Morrell, Wynter; Krans, Burns, Withey (Bishop 71). Subs not used: Cable, Paice, Fry, Horgan.