A warning for slow play helped speed Michael Sims to another victory at the US Amateur Golf Championship yesterday.

The 22-year-old Islander, who had carded a tremendous six under par 66 to reach yesterday's match play stage in Atlanta, Georgia, had traded holes with American Steve Christophel during the opening stretch of their match play clash.

The pair halved the opener but by the time they reached the fourth the Islander was two down.

The score remained the same until the seventh when a par by Sims enabled him to grab the hole but he slipped back again when he three putted on eight.

Sims won the ninth and it was at the 10th where the pendulum, albeit cautiously, began to swing his way.

Although he actually went on to win the hole Sims said Christophel appeared to be "disturbed" by the intervention of a tournament official who warned both players for taking too long to play their second shots.

Speaking from his hotel room after returning from the course, Sims said he felt the warning, though justified, was more the fault of his opponent than himself.

"From our drives off the tee I was probably about 20 yards up ahead of him. But I was right in front of him so I couldn't go up to my ball and take a look at it," he explained.

"It was a par five and we were both in the rough. He took a long time to decide what he was going to do. By the time I got up to my ball and had checked out all my options it seemed like I took a long time. But if I had just walked straight up to my ball I could have (played it sooner). He was taking forever and a day to hit his shot and I then had to go through the yardage and all the rest of it."

When he eventually got round to playing the ball, Christophel sunk a birdie putt to go two-up, Sims settling for par.

"I won 11 with a two putt par and on 12 he conceded because he was putting for double bogey," he said.

The next hole the Islander birdied to go one-up, but they were back all square after 14.

On 15 Sims flew the green and suffered a bogey to his rival's par.

The par four 16th saw 20 feet between Sims' ball and the hole.

"It was a little right to left and was one of those putts that you have a look at and you just get that feeling," said Sims, who went on to birdie that hole and par the final one for the victory.

"I could have two-putted (the 18th) from about four feet because he had made bogey already and I was one-up. I could have made bogey along with him and still won."

Sims said despite the up and down nature of the game there was never a point where he felt he had lost.

"Match play is funny it can change just like that, like it did today. He goes from winning 15 and hitting a really good drive on 16 and probably feeling like he might have me in the bag, or at worst halve me. And then the birdie on 16 and we go back to even and he three putts on 17 and all of a sudden he is one-down. That was pretty nice, it was really good to go to 18 with a one-up lead."

Having said he struggled to his six under finish on Tuesday, Sims said he hadn't fared much better yesterday.

"It was relieving. Because I really didn't hit the ball that great today and it was nice that I just made it through," he said. "I didn't hit the ball great but it was a little bit better than yesterday and I think it's slowly coming around. I feel a little more comfortable with every shot."

Sims tees off at 9.30 a.m. EST today against Simon Nash of Australia, a three and two winner over Graeme McDowell of Northern Ireland yesterday.

Asked if he had exceeded his expectations this week, Sims said definitely not.

"I try not to limit myself. If I didn't believe in myself then I wouldn't have got to where I am," he said.

"You have to keep on believing in yourself and trusting in yourself."

While he was playing yesterday Sims collected quite a following.

"I had quite a few people out there today - my mum, dad, sister, a buddie of mine from college, my godparents, Eddie and Jan Marshall. There was a lot of people actually out there," he said. "I love a gallery."

The crowd will be out again today and win or lose Sims promised one thing: "There'll be a big smile on my face no matter what I do."