Mansfield Tn 2 (Williams 20, Speight 25), Oxford Utd 1 (Constable 74)
Oxford United's first defeat of the season had to arrive sometime and perhaps manager Chris Wilder had seen it coming on Saturday afternoon as he saw one or two bad habits set in.
At Field Mill last night they were not sharp enough in too many areas of the pitch, and Mansfield achieved a deserved victory thanks to two goals in five minutes midway through the first half.
The Stags were quicker in the tackle, and to the second ball, and the U's couldn't live with their tempo in the first half.
James Constable pulled a goal back in the 73rd minute with a first-time shot from Adam Murray's chip into the box.
They threw everything into trying to get an equaliser and Jamie Cook hit the bar for the second time in the game with a header.
But despite strong pressure at the end, they just couldn't get a second goal.
United were left stunned by the two goals in the first half, but they had been coming.
And yet, just seconds before, Matt Green missed a great chance when Damian Batt's pass put him clear.
Green chose to shoot early rather than go around the keeper, and his deft chip did indeed clear Alan Marriott, but went wide.
Just how costly that was to prove was seen immediately as Ryan Williams fired ther Stags in front.
Ryan Clarke saved Jake Speight's initial shot but the ball ran out to Ryan Williams, who chipped over the keeper and into the goal.
That was the first goal Oxford had conceded for 560 minutes but they shipped another one moments later when they were totally stretched at the back.
It stemmed from a poor touch by Ryan Williams. Batt looked to have won the ball but couldn't get it away, and in an instant Rob SDuffy laid it off to Speight free on the right side of the penalty area, and Speight thumped the ball high into the net.
Despite Mansfield Town claiming he would miss the game with an ankle injury, Duffy did start, lining up alongside Speight in the Stags' attack.
Steve Kinniburgh returned at left back for the U's.
Mansfield started the game well and were unlucky not to take the lead after a quarter of an hour when Speight shot against the post from 14 yards after some good interplay, amidst some fairly desperate defending.
Left winger Louis Briscoe was causing big problems with his trickery, and Speight fired wide from his cross just a few minutes earlier.
Speight should have done better but was unable to control the ball after another good Briscoe delivery, this time from the right.
The home team had dominated the first half and defensively, the U's had been poor.
They hadn't enjoyed much possession to set up attacks either, Mansfield quicker to the ball and winning most of the 50-50 challenges.
Green went close with a shot at the near post that deflected just wide, after Mark Creighton won a header in the box.
Two minutes before the break, Jamie Cook drove a 30-yard shot against the bar, with Alan Marriott completely beaten, from James Constable's knockdown.
Had that gone in, it would have given the visitors a great boost, but they trudged off at the interval licking their wounds.
The second half had only just begun when Marriott fell awkwardly, over his own teammate Gary Silk, but he got to his feet following treatment from U's physio Jon Brown, his Mansfieeld counterpart attending to his own player.
Wilder then made a tactical substitution, throwing on Jack Midson, in place of Kinniburgh, and changing to 4-4-2, wit Simon Clist and Cook dropping back.
But it was the home side who went closest to scoring the next goal, Briscoe darting past three players on a run into the box, and only denied by a fine save from Clarke.
It needed someone to make sometyhing happen for the visitors to get back into that game, and that someone was Murray. He gained possession, picked hios centre forward but with a clever pass, and Constable buried a left-footed shot for his ninth goal of the season.
But that was all they could muster, despite Cook's great efforts, and it meant a first away defeat of 2009 for Chris Wilder's Oxford United.