Jamie Guy and James Constable struck in the second half to send Oxford United through to the FA Cup first round.

But they were guilty of some woeful finishing before and after those goals.

This fourth qualifying round win was marred by a bad injury to right back James Clarke, who was stretchered off in the last minute after a bad tackle by Hayes & Yeading striker Will Hendry, which earned him a booking.

The Blue Square South side were left kicking themselves that they failed to take some great first-half chances before United eventually wore them down in the second half.

It was a game that featured a catalogue of misses in front of goal - by both teams.

And Guy was the biggest culprit with four excellent opportunities missed before he eventually fired Darren Patterson's side ahead on 57 minutes, his shot deflecting off a defender to loop over unfortunate keeper Delroy Preddie.

Constable then sealed the U's passage when he side-footed home Yemi Odubade's right-wing cross in the 72nd minute, just moments after Odubade had come on as a sub.

But Oxford got away with it in the first half, when Hayes & Yeading could easily have been two goals up, as they attacked with menace and in numbers.

Matt Ruby volleyed just past the post when the visitors forced the game's first corner, and Ram Marwa missed the target with a free header from a great position from Danny Allen-Page's right-wing cross.

Oxford United were too casual in a lot of their play. Guy took the ball past keeper Delroy Preddie but simply overran it and lost a great opportunity.

And at the other end experienced keeper Billy Turley was fortunate to get away with a sloppy clearance, which hit Kieran Knight's back, as Will Hendry then fired wide.

A few minutes later Turley saved from Josh Scott when he wriggled his way through.

In the second half, the professionals' fitness began to tell and they carved out chance after chance, but had the home crowd groaning with some woeful finishing.

Lewis Haldane blazed two wide, Odubade missed, Matty Taylor went round the keeper but then slipped over . . . but Oxford United finished very comfortable winners in the end.

Oxford Utd: Turley; Clarke, Foster, Willmott, Carruthers; Haldane (Dobson 90), Murray, Trainer, Deering, Constable (Taylor 85), Guy (Odubade 70).

Att: 2,521.