A sixth red card of the season proved costly as 10-men Mansfield were well beaten at home by high-flying Oxford United, who took over at the top of the table with this victory.
Jamie McGuire was red-carded on 23 minutes for diving into a tackle on Sean Rigg with Mansfield already a goal behind.
Lee Stevenson did end the League goal drought in first half stoppage time at 472 minutes to volley the 10 men level.
But sub James Constable quickly had the visitors back in front even deeper into stoppage time with his 100th goal for Oxford, two minutes after coming on, and once the outstanding Ryan Williams grabbed a third on 66 minutes, it was all over.
It was a seventh League game without a win for depleted Mansfield while, for Oxford, it continued a fine run of form on the road, now having won five and drawn two of their last seven away games.
Oxford played most of the football on show with Stags too often kicking the ball long with no recognised big target man to hold it up.
Oxford also deserve credit for their sturdy defending.
Jake Speight made a shock return to the Mansfield line-up. The striker had banged in five goals in six games on loan to Conference neighbours Alfreton Town but was this morning recalled by Mansfield to replace Ollie Palmer, who tore a hamstring last weekend.
There were also two changes at the back as Lee Beevers and John Dempster returned from suspension at the expense of George Pilkington and John McCombe.
The visitors included former Stags defender Johnny Mullins.
Everyone was hoping Stags would have been lifted by that fine 8-1 away FA Cup win at St Albans last weekend.
But in the end they were found wanting against a side that looks very likely to figure in the end of season promotion battle.
An even opening saw Stags force the first corner from a deflected Clucas shot on four minutes, but it proved an easy catch for the unchallenged Clarke.
Rigg needed treatment for a McGuire challenge which saw the Stags man lectured and ordered to go over and apologise to the fallen Oxford man.
Stags forced a second corner on nine minutes which Jennings curled to the near post and Stevenson’s flicked header forced Clarke into a reaction save.
A Daniel free kick, from a central position inside the D, saw his effort deflect wide for another corner.
However, the Stags fell behind after a mistake from keeper Marriott on 12 minutes.
Rose made a good run down the right and cut inside for a low shot that looked routine for Marriott.
But the keeper, diving to his right, failed to hold the ball and it ran loose for an easy tap-in for Rigg.
Soon after, Rigg put in a dangerous cross from the left that Marriott watched all the way as it bounced over off the top of his bar.
Oxford lost Whing to injury after 19 minutes, Hall replacing him.
The visitors were already time-wasting at this early stage and Stevenson eventually ran to fetch the ball for an Oxford throw letting the assistant referee know what he thought of it as he ran past him.
Mansfield’s afternoon worsened on 23 minutes as McGuire was shown a straight red card for a thundering tackle on Rigg.
The Oxford man stayed down and players from both sides began to jostle each other.
Eventually Raynes and Speight were also shown yellow cards.
Howells was well wide with a header from a long Jennings free kick from the left.
Williams was allowed to run unchecked down the centre and get away a shot that flew well over the angle.
Dempster needed attention for a bang on the head as Oxford cleared Mansfield’s fourth corner.
On 37 minutes Mullins almost doubled the visitors’ advantage as he got goalside of Beevers to meet a Hunt free kick with a firm header that wasn’t far wide of the far post.
Stevenson’s name was added to the book on 38 minutes for delaying an Oxford free kick with home fans baying at the official, who was getting a lot of his decisions wrong both ways.
Smalley was the latest to buy Oxford some time as he stayed down after whacking Stevenson in the back for a foul and then going down himself.
At this stage the visitors were making the most of their man advantage by holding onto the ball well and forcing Stags to chase.
In the final minute of the half Kitson saw his shot deflect wide off a team mate after Marriott had only been able to get one hand onto a Williams cross.
A stop-start half saw eight minutes added on.
And halfway through that the 10 men were on level terms.
Dempster got a head onto a long Jennings free kick which was cleared only as far as Stevenson who, from 16 yards, sent a crisp volley into almost the centre of the goal.
Speight was just unable to control a long Daniel ball soon after and it ran through to the keeper before he could capitalise.
It was stirring stuff all of a sudden with the home fans loudly behind the players. But the comeback was halted very quickly.
Strike ace Constable was sent into the action six minutes into the added time and within two minutes with almost the last kick of the half, put United back in front.
A neat passing movement on the right ended with Williams feeding a disguised pass inside on the right of the box and Constable dispatching a low finish which eventually found the net off the inside of the left post.
After the break, Stags were lucky that Hall’s low cross didn’t end up in the net after a deflection off Beevers that saw it pass inches wide with Marriott nowhere near and the goal gaping.
United looked dangerous and Jennings then had to dive in to get a block on a Williams shot while Constable guided a header narrowly wide from a Kitson far post cross.
Williams headed a Newey cross onto the roof of the home net before Stags finally sparked into action on 52 minutes as Speight chased onto a through ball on the right and sent in a vicious shot that Clarke had to turn over.
Marriott was then equal to a Constable shot from 20 yards that looked set to find its way under the bar until he fingertipped it over.
Constable sliced a near post shot wide from a Rose pass after Jennings failed to clear.
Kitson was added to the book on 61 minutes for a late tackle on Clucas.
Clarke was left stranded after leaving his box to beat Speight to the ball only to see it reach Clucas. But the youngster was quickly faced with a succession of defenders and his eventual shot-cum-pass drifted away harmlessly.
Oxford bagged a killer third goal on 66 minutes. Rigg crossed hard and low from the left by-line and Williams beat Jennings to the ball to turn it home from close range.
Mansfield almost pulled one back straight away as Dempster headed on a long Jennings throw for Speight to leap well and send his header straight at Clarke.
Clucas whipped a shot wide from 20 yards on 77 minutes as time continued to run out on the home side.
The game then petered out with disappointed home fans draining out the stadium.
STAGS: Marriott; Beevers, Sutton, Dempster, Jennings (Meikle 72); Clucas, Howell, McGuire, Daniel; Stevenson (Murtagh 85), Speight. Subs not used: McCombe, Rhead, Deakin, Andrew, Pilkington. OXFORD: Clarke, Newey, Raynes, Rigg (Ruffels 77), Kitson, Smalley (Constable 45+6), Hunt, Williams, Whing (Hall 19), Rose, Mullins. Subs not used: Davies, Crocombe, Bevans, O’Dowda.
REFREREE: Charles Breakspear of Surrey.
ATTENDANCE: 3,831 (769 away). CHAD STAGS MAN OF THE MATCH: Junior Daniel.