American veteran Todd Martin was cheered to victory by the partisan crowd in his US Open quarter-final win over Swede Thomas Johansson.

Martin, who lost in the final to Andre Agassi last year, used a single service break in each of the first two sets to take a comfortable lead.

Martin was cruising but a loss of concentration saw the Swede, ranked 91st in the world, claw his way back into the match at Flushing Meadows.

Fans were worried Martin was tiring after his epic fourth round match against Carlos Moya, when he fought his way back from two sets down.

Johansson, sensing Martin was losing his composure, broke the American in the fourth set.

It looked as though another five-setter was on the cards but Johansson dramatically lost his serve after being ruffled by a controversial umpire's decision.

Unseeded Martin stepped up a gear and broke Johansson in the 12th game to set up a semi-final clash with sixth seed Russian Marat Safin.

After the match, a relieved Martin said: "He played a great third set.

"He served great and made a couple of good plays. I didn't do well on my volleys. I lost momentum and he picked up.

"I was able to scrap some ugly points and put some extra pressure on him. I wanted to make him see me. I came as much I as I could to the net."