OXFORD United's strong finish to the calendar year continued as they were too good for AFC Wimbledon, but the result was soured by a red card for James Constable.
A quick double from Sean Rigg and Alfie Potter put the visitors in charge at half time.
After weathering a storm from the hosts, United made sure of the points when Tom Craddock pounced on an error to make it 3-0.
It looked a perfect away day for the visitors, but Constable's straight red card for an alleged elbow complicated the final 20 minutes.
The U's defended well to claim a hard-earned clean sheet, claiming a second win in four days to extend their unbeaten run to nine games.
Heavy rain put the game in doubt, but once the game started the surface coped well, for which Wimbledon deserve credit.
United made just one enforced change to the side which started the 3-1 win at Exeter City in Boxing Day.
With Liam Davis injured and Tony Capaldi suspended, Luke O'Brien came into the side at left back for the first time since October.
After an even opening, United were the first to threaten.
Potter had two sights of goal, dragging one effort wide and drawing a smart stop from veteran goalkeeper Neil Sullivan with the other.
In between the winger set up Rigg, whose sweetly-struck volley flew just wide.
Wimbledon were given a foothold in the game by the award of two questionable handball decisions on the edge of United's box.
Both were wasted, with Paul McCallum blasting over and U's goalkeeper Ryan Clarke catching Rashid Yussuff's tame effort.
Around the half hour mark the visitors began to control of the game.
Potter was at the heart of United's most dangerous moments and the winger was key to a clinical move which broke the deadlock on 32 minutes.
Collecting the ball from Craddock, he cut across the Wombles' area, delaying his pass expertly to slip in Rigg, who lifted the ball over Sullivan and into the net.
Within five minutes the pair's roles were reversed. Rigg crossed from the left and Potter, the shortest man on the pitch, rose to head past Sullivan.
The cushion gave United a swagger on the ball, but Wimbledon almost pulled a goal back on the stroke of half time.
Jack Midson worked some space 20 yards out and his left-footed drive skidded a whisker wide of Clarke's left-hand post.
The home side came roaring back into the game after the break in search of a lifeline.
United had to dig in to protect their lead and needed a brilliant clearance on the goal line by Peter Leven to keep Wimbledon out.
Yussuff had a clear sight of goal on 55 minutes, but the midfielder shot wide from 12 yards to let the U's off the hook.
The key moments came just after the hour mark and revolved around Will Antwi.
The Wombles centre back had a glorious chance to score from Ajala's cross, but he headed wide.
When United broke forward Antwi attempted to head the ball back to Sullivan, but he could only find a lurking Craddock.
The striker could not believe his luck and gratefully buried the ball into the net.
The points looked in the bag for the visitors, but midway through the half they were rocked by a dismissal.
Antwi went down after an aerial challenge with Constable and the referee adjudged the striker had led with his elbow, producing a straight red card.
It looked a harsh decision, particularly as Antwi recovered very quickly after the card was shown.
Wimbledon had just over 20 minutes to make their numerical advantage count.
United showed plenty of appetite to defend, though and kept clear chances to a minimum.
Up front, substitute Josh Parker did well to occupy the centre backs in a lone role.
A clean sheet, and the three points, were well deserved, but Constable's sending off took the edge off the joy.
Oxford Utd: Clarke, Batt, Raynes, Wright, O'Brien, Potter (Duberry 87), Cox, Leven, Rigg (Parker 77), Constable, Craddock (Heslop 68).
Unused subs: Brown, Worley, Forster-Caskey, Marsh.
Wimbledon: Sullivan, Osano, Antwi, Mambo, Cummings, Long, Yussuff (Jolley 73), Meades, Ajala (Kiernan 82) McCallum (Prior 72), Midson.
Unused subs: Jamiez-Ruiz, Balkestein, Mitchel-King, Hervel.
Referee: Lee Collins.
Attendance: 4,401 (749 visitors).