Erhun Oztumer and Tyler Roberts were on target as Walsall recorded a first away win of 2017 with victory at Oxford.
The Saddlers dominated the first half, taking the lead on 32 minutes when Oztumer tapped in a Joe Edwards cross.
Oztumer and Tyler Roberts spurned chances before the latter doubled our lead with a low finish eight minutes after the break.
Ryan Ledson halved the deficit with a 78th-minute penalty but the visitors deservedly held on for all three points.
Jon Obika looked lively for the hosts early on, first being denied by an expert sliding tackle from James Wilson before shooting tamely at Mark Gillespie from distance.
The game’s first real chance came on 23 minutes, Kieron Morris drilling a low right-footed shot towards the bottom corner which U’s keeper Simon Eastwood fumbled onto the post.
The Saddlers were enjoying the better of proceedings and took the lead just past the half-hour.
Joe Edwards skipped past John Mousinho on the left and delivered a teasing cross which looped over Eastwood and was tapped in by Oztumer from virtually on the line.
With the visitors well on top, Oztumer could have doubled his and Walsall’s tally when he sliced a first-time effort wide from Morris’ centre.
The diminutive midfielder was involved again shortly after, exchanging passes with Tyler Roberts before hitting a low drive which Eastwood claimed.
The dominant visitors should have put the game to bed on the stroke of half-time.
First, Zeli Ismail showed quick feet before slipping in Roberts, whose low strike was saved by Eastwood to his right.
And the home custodian thwarted Walsall again moments later, spreading himself well to block Oztumer’s effort when one-on-one.
The elusive second goal finally arrived eight minutes into the second half, Oztumer threading a lovely pass through to Roberts, who finished low across Eastwood and into the far corner.
Pep Clotet’s side pushed for a response, with Rob Hall and James Henry having attempts easily held by Gillespie.
Instead, the Saddlers could have made it 3-0 when Roberts’ powerful shot on the turn was acrobatically tipped over by Eastwood.
United had a big chance to halve the deficit 20 minutes from time but Gillespie produced a terrific one-handed save to flick James Henry’s hooked volley over the bar from a corner.
And Oxford had another opportunity seconds later, Gino Van Kessel prodding a shot against the foot of the post before the Saddlers eventually cleared.
The U’s grabbed the goal they had been threatening with 12 minutes remaining, Ledson sending Gillespie the wrong way from the penalty spot after Luke Leahy had brought down Hall.
But the hosts were unable to build on that goal as Walsall held on for a deserved win.
Team: Gillespie, Devlin, Guthrie, Wilson, Leahy, Chambers, Ismail (Kinsella 78’), Edwards, Oztumer, Morris, T Roberts (Bakayoko 73’).
Subs not used: L Roberts, Donnellan, Flanagan, Kouhyar, Agyei.
Attendance: 6,895 (403 Walsall supporters).