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.

Michael Skubala hailed his “ruthless” Lincoln side after they thrashed Cambridge 6-0 to extend their unbeaten Sky Bet League One run to 12 matches.

Braces apiece from Jack Moylan – his second in two games – and Joe Taylor, plus further strikes from subs TJ Eyoma and Dylan Duffy saw the Imps close to within three points of the play-off places.

“I thought we were ruthless from start to finish,” gushed Skubala. “I was very impressed and even at the end you could see how much these guys want to win.

“We’re a tough side to play against, we have a ruthless streak to us and the mentality of the group is fantastic at the moment.

“We talk about starting the game quickly, making sure we’re on the front foot and credit to the lads, they did that really well. I thought there were some brilliant performances out there to a man.

“We need to keep our feet on the ground, though. We haven’t cracked it. We have to do it game by game and go again. It’s going to be really tough game on Saturday against Bristol Rovers.

“But we’re putting a marker down and if anyone slips up, we’ll be there.”

Moylan fired City into the lead after just three minutes. Sean Roughan’s cross into the box fell to Lasse Sorensen initially, but the ball eventually found its way to the Irishman who smashed a shot high into the roof of the net.

Moylan doubled the lead after 25 minutes, confidently slotting a low shot past Jack Stevens after a delightful Ethan Erhahon pass.

It took the Imps just three minutes of the second half to go 3-0 up, with Danny Mandroiu’s sublime ball across United’s area finding an unmarked Taylor who had the easy job of steering the ball into the net.

City added a fourth after 75 minutes when Moylan’s brilliant through ball set up Taylor to dink a shot over Stevens and into the net.

Eyoma then fired home after Teddy Bishop’s shot was initially blocked before Duffy rammed a shot through Stevens’ legs to complete the rout.

It was a humbling experience for Cambridge boss Garry Monk in only his second match in charge.

“I am hugely frustrated, I did not expect that all,” admitted Monk. “I expected us to build off the back of an OK performance last Saturday.

“It was just self-inflicted – all those goals were very poor ones to concede. You can’t concede goals how we did tonight. You might see one or two of them conceded like that, but not four or five.

“We made far too many mistakes. We rather gifted them a lot of their goals and the performance has given me some food for thought.

“I need to think a bit more what we need to do away from home. Once a couple of the goals went in, we were a bit tepid after that. We were a yard or two off it.

“We played against a good side, but we made it easy for them.”