Marvelous Marvin Robinson helped get Oxford United back on the goal trail in his comeback game last night.

The big striker won a 28th-minute penalty which Rob Duffy converted as the U's edged past Lewes in their delayed FA Trophy first-round replay.

Robinson was getting his first taste of competitive action for nearly four months after a serious knee injury.

But he looked sharp and hungry, and as though he had never been away, as he rolled Lewes right back Steve Robinson at a throw-in from Rufus Brevett, and was scythed to the ground.

After Lewes's Robinson was yellow-carded for the foul, Duffy then sent the Rooks' rookie goalkeeper Jack Adams the wrong way from the spot for his 16th goal of the season, and Oxford's first in this competition.

The Conference South side's manager, Steve King, was seething that the FA had turned down his club's request for special dispensation to sign a goalkeeper after their regular recent stopper was recalled from his loan by West Ham.

Less than three hours before kick-off, King was still planning to use one of his outfield players, defender Leon Legge between the sticks, but 17-year-old Adams, Lewes's youth-team keeper, was hurriedly driven over from Sussex to play in the match.

It must have been a daunting prospect for a youngster who has never played a senior match to suddenly find himself thrown in at the Kassam Stadium, but he was greatly helped by Oxford's reluctance to test him with shots in the first half.

Robinson's left-footed effort in the opening few minutes bobbled wide, and when Duffy headed Yemi Odubade's cross back across goal to Robinson in a decent position, he shinned his shot wide.

Even more frustrating for the home fans in a predictably small gate of just 2,194, was Duffy's reluctance to shoot when Robinson found him with a neat header inside the area midway through the half. Shielding the ball, with his back to goal, he waited an age for support rather than try to turn and blast it.

Jim Smith had rested Eddie Anaclet from his starting XI and used Gavin Johnson in a holding midfield position.

With Odubade operating as the wide striker on the right, it was a 4-3-3 formation with Robinson in the centre of the attack and Duffy to his left.

Carl Pettefer was soon passing tidily in midfield to orchestrate United's attacks in a difficult wind, while Andy Burgess found himself tightly marked again.

Moments after they had taken the lead, Burgess was hacked to the ground by Gary Holloway, which earned the Lewes midfielder a booking.

Marvin Robinson was one of three U's players who besieged the ref for what they felt was an over-the-top challenge on Odubade.

So it was ironic that Robinson should also find his way into the official's notebook early in the second half, for what the ref thought was an over-the-top challenge just outside his own box - when he appeared to have won the ball.

Anaclet replaced Burgess for the second half, with John Dempster moving into midfield.

Smith had clearly urged them, during the interval, to shoot more as Johnson and then Matt Day let fly from distance, but well off target.

Lewes skipper Paul Kennett went closer with a rifled left-footed drive just before the break that just cleared angle of post and bar.

With 15 minutes left, Odubade was through on goal, albeit with chasing defenders on either shoulder, but he screwed his shot well widewide it ended up closer to the corner flag than the frame of the goal.

In the closing minutes, Odubade raced down the right and laid it on a plate for Duffy with a square pass into the box, but United's leading scorer was chopped from behind by Steve Robinson - yet the ref wouldn't have it.

It was the same with Marvin Robinson in the final minute. He raced through on goal, only for Legge to deny himwhip the ball away.

By then Oxford were grateful to Johnson for whipping the ball away off his own goalline when the part-timers threatened to snatch an equaliser to take it into extra time.

The U's nosed through to the second round, and a home tie against Halifax on Saturday.

But just one shot on target - the penalty - wasn't very good.