A goal from Holly Manders with a little under half an hour to go was the only goal of the game as AFC Bournemouth’s remarkable 1,081-day, 59-game unbeaten run came to an end.
Helen Bleazard’s side remain in third in the National League Southern Premier Division, trailing league leaders Watford by five points with two games in hand, and second placed Plymouth by four points with three games in hand.
There were few clear-cut chances for either side in the opening exchanges, but the Cherries threatened the Oxford goal with 18 minutes on the clock.
Jenna Markham shot towards goal after a good Charlotte Harris run but it deflected into the arms of keeper Beth Wookey.
Two minutes later, Wookey was again called upon to deny Georgia Wilson, whose low effort was kept out by the keeper.
Oxford threatened Erin Foley’s goal, with the ball flashing across the goalline on the half an hour mark and Foley was in action to comfortably claim a Manders cross.
The sides entered the break without score, and Bleazard introduced Kenni Thompson for Freya Meadows Tuson at the interval as they sought an opening goal.
A big chance went the way of the hosts eight minutes after the resumption.
Maisy Barker rounded Foley after the Cherries had given the ball away, but her ball across goal was not met by a teammate and Bournemouth survived.
Elena Cole and Zoe Barratt were introduced for Molly Barron-Clark and Markham just after the hour mark.
But the Cherries fell behind on 62 minutes, as Mandas finished into the bottom corner as she capitalised on a loose ball.
Bournemouth sought a response and they went close.
Sophie Quirk saw a deflected effort go just wide of the far post, and, from the resulting corner, Amber Treweek curled a shot goalwards that Wookey was able to tip past the post.
The Cherries were handed a late boost as Oxford’s Nicole Barrett was sent off for a second bookable offence, but they couldn’t capitalise on their player advantage in the dying minutes.
The final whistle went and the Cherries were beaten for the first time in the league since March 5, 2023.