Goals late in the first half from Mark Harris and Ruben Rodrigues gave the U’s a 2-0 victory, as the League One play-off winners defeated their Premier League-bound visitors.

Saints started the game on top, as Oxford goalkeeper Jamie Cumming twice denied Sam Amo-Ameyaw, while Charly Alcaraz went close from long range, but injuries to Sékou Mara and Kamaldeen Sulemana disrupted their rhythm.

With Saints temporarily down to ten men after Kamaldeen hobbled off, the hosts took advantage to edge in front when Harris converted Rodrigues’s right-wing cross ten minutes before half time, before a stray pass invited Rodrigues to double the lead soon after.

Russell Martin made seven of his ten substitutions on the hour mark, but Joe Aribo’s low shot just past the post was the closest his side came to finding the net.

Saints started with Ryan Manning in a central midfield role, and the Irishman was soon pulling strings, twice creating openings from balls over the top of the defence.

The first invited Cumming to race out of his area, forcing him to head the ball but only as far as Amo-Ameyaw, who had the time to take a touch and guide the ball back over his head, but couldn’t execute the finish, which lacked the elevation to clear the stranded stopper.

Charlie Taylor in action at the Kassam Stadium

Then a similar Manning pass found Kamaldeen breaking into the box, but the winger stalled when there was a chance to cut the ball back for the onrushing Manning, who followed his pass, and the attack lost its momentum.

Oxford’s left-winger, an unnamed trialist, sent a low shot skidding wide of Alex McCarthy’s goal, before Saints smuggled the ball behind for a corner when Harris broke through on the right side of the box for the hosts.

For Saints, Alcaraz, always direct, injected some urgency with a touch out of his feet and sudden shot that had Cumming worried, diving to his right and relieved to see it zip wide.

Saints pieced together their best move to date midway through the half when Amo-Ameyaw combined with the overlapping James Bree down the right, exchanging passes before Amo-Ameyaw forced another save from Cumming.

Martin turned to his bench earlier than he would have liked when Mara went down and was unable to continue, prompting Tyler Dibling to step into the striker role.

Saints then began to endure a difficult spell. Another shot from Oxford’s trialist flashed narrowly wide before Kamaldeen departed with an injury of his own.

In the time it took Saints to prepare his replacement, Rodrigues delivered a cross from the right that took the slightest touch off Charlie Taylor, inviting Harris to score from eight yards.

The travelling Saints fans packed out the away end

The visitors got themselves into more trouble shortly before half time when Ronnie Edwards’s square pass was intercepted by Rodrigues, who picked his spot with a firm side-foot finish into the bottom corner from 20 yards.

The half-time interval saw the return of Adam Armstrong in place of Alcaraz, as Saints began to push Oxford back.

Edozie’s first gallop down the left nearly forced an own goal, before the influx of changes arrived on the hour mark, sparking an immediate chance for one of the new arrivals, Aribo, who drilled wide from Armstrong’s pass.

Saints dominated the possession thereafter, but were unable to find a way through as Cumming denied Armstrong late on.

Oxford United: Cumming, Kioso (Long 45), Moore (c) (Thorniley 62), Brown (Golding 62), Bennett (Leigh 62), Vaulks (McEachran 45), Brannagan (McGuane 62), Goodrham (El Mizouni 62), Rodrigues (O’Donkor 62), Trialist (Goodwin 62), Harris (Sibley 62).

Goals: Harris (35’), Rodrigues (42’).

Saints: McCarthy (c), Bree (Sugawara 60), Edwards (Harwood-Bellis 60), Wood (Bednarek 60), Taylor (Stephens 60), Charles (Smallbone 60), Manning (Downes 60), Amo-Ameyaw (Aribo 60), Alcaraz (Armstrong 45), Kamaldeen (Edozie 36), Mara (Dibling 23).

Referee: Gavin Ward.

Attendance: 5,273.