Oxford United stretched their unbeaten run of friendlies to six matches with a hard-fought 2-0 victory against Championship side Birmingham at teh Kassam Stadium on Tuesday night. Second-half goals from new signing Ryan James and winger Alfie Potter paved the way for victory against Chris Hughton’s Birmingham, who only have themselves to blame after spurning a host of chances. James opened the scoring when Damian Batt’s free-kick was only half-cleared by Birmingham’s defence, with Potter making it 2-0 when he volleyed in a cross from fellow substitute James with style.

Birmingham boasted a number of internationals and experienced players including Ben Foster, Steven Carr, Curtis Davies and Liam Ridgewell.

There was a surprise from the U’s before kick- off with Andrew Whing replacing former Blues youngster Asa Hall in the starting line-up.

Birmingham, backed by a sizeable noisy contingent of followers, almost took the lead in the opening minutes, Adam Rooney firing wide after Keith Fahey’s shot was cleared for a corner by Damian Batt.

At the other end, Werder Bremen triallist Liam Boyce, who came on as sub in the U’s 1-0 win against MK Dons on Saturday, had an opportunity to make a name for himself, but blazed over.

Seconds later, centre back Harry Worley, who was brought in for Michael Duberry, booted Fahey’s blistering shot off the line.

Davies headed Fahey’s corner against the bar as Blues built up a head of steam.

Ryan Clarke dived at the feet of Rooney as he broke for goal and it was the visitors who should have gone ahead on 32 minutes after Rooney was put through but after beating Clarke to the ball, he smashed his shot over.

United then put on some pressure of their own, with James Constable firing wide of Foster’s goal.

Birmingham continued to look the more dangerous and Clarke pulled off a brilliant save with his right hand to keep out another Fahey piledriver.

The woodwork rescued United again when Chris Burke’s left-footed curler hit the bar, with Clarke beaten.

After the break, United made a couple of changes with triallist Liam Davis coming on for Josh Payne and Hall replacing Simon Clist.

Carr almost gifted the U’s the lead when a mix-up with Foster saw the ball trickle towards goal, but the Ireland international cleared the danger.

The introduction of Potter turned the game in United’s favour. The elusive winger was fouled as he broke down the left and from Batt’s resulting free-kick, the ball fell to James, who smashed it home past Foster.

United were forced into a change when Worley was carried off on a stretcher with a knee injury, though it is not thought to be serious.

His replacement, Michael Duberry, was soon forced into action as Blues pressed for an equaliser.

Potter was proving a menace to Birmingham’s def-ence with his direct running and he got in a tremendous cross, but no-one was there to stick it in the net.

U’s skipper Jake Wright, who carried on from his excellent showing against MK Dons, blocked Akwasi Asante’s well-struck shot.

And it was all over for Blues when Potter volleyed in a super left-wing cross from James at the far post.

Deane Smalley then set up fellow sub Jon-Paul Pittman, who should have made it 3-0 as the game entered injury time, but Ridgewell made a brilliant challenge as the ex-Wycombe man was about to pull the trigger.

Oxford Utd: Clarke, Batt, Tonkin (James 61), Wright, Worley (Duberry 75), Payne (Davis 45), Clist (Hall 45), Whing, Craddock (Potter 60), Constable (Pittman 76), Boyce (Smalley 60). Subs: Potter, Whing, Capaldi. Birmingham City: Foster, Carr (Hubbins), Davies, Caldwell (Valles), Ridgewell, Burke (Redmond), Mutch, Gomis, Fahey, Rooney, Asante. Subs: Doyle, Dann, Murphy, Redmond, Madera, Kerr, Ozturk. Attendance: 2,744.