Lincoln kept alive their League One play-off hopes with a crucial 1-0 victory over sixth-placed Oxford at the Kassam Stadium.
Danny Mandroiu hit the winner from the penalty two minutes into the second half after Ruben Rodrigues fouled Ben House.
They held out despite having substitute Dylan Duffy sent off for a second yellow card seven minutes from the end.
It was a must-win game for the Imps after their home defeat by Wigan at the weekend and they started the better.
Paudie O’Connor forced goalkeeper Jamie Cumming into a save with a far-post header at a corner and Freddie Draper headed wide from close in.
The visitors suffered a blow when Reeco Hackett had to go off with an arm injury after what looked an innocuous challenge.
As the half wore on Oxford settled and keeper Lukas Jensen twice saved from Tyler Goodrham and Mark Harris also went close twice as the U’s turned up the heat.
But City also looked dangerous and Draper squandered another good opportunity from eight yards.
The U’s were caught cold at the start of the second half when they conceded the spot-kick, hammered home by Mandroiu to Cumming’s left.
Cameron Brannagan added an extra dimension for United when he came off the bench and he cut in from the left to hammer a fierce drive that Jensen did well to save.
But Lincoln defended resolutely for a victory that keeps their season going.
