AUCKLAND, New Zealand -- Maybe Michael Chang's luck is about to change.

Once ranked No. 2 in the world, Chang has been mired in mediocrity for more than a year. On Thursday, he got a break when Sweden's Magnus Gustafsson retired from their Auckland Open quarterfinal match with a right knee injury.

Chang won the first set 7-5 before Gustafsson took the second 6-3. With Chang leading 1-0 in the deciding set, the match was halted for 59 minutes before of rain.

When play resumed, Gustafsson was unable to continue.

Three seeded players were defeated, including defending champion and sixth-seeded Sjeng Schalken of the Netherlands, who fell to Argentinean Gaston Gaudio 6-1, 6-2.

Spain's Juan Balcells, who beat top-seeded Tommy Haas in the second round, reached his first ATP Tour semifinal by beating No. 7 Juan Carlos Ferrero of Spain 4-6, 6-3, 6-1.

No. 2 Magnus Norman of Sweden, ranked 15th at the end of last year, extended his record against eighth-seeded Marc Rosset of Switzerland to 3-0 with a 6-2, 6-2 win. It will be the second semifinal in as many weeks for Norman, who reached the final four at Adelaide last week, where he lost to countryman Thomas Enqvist.

Schalken was disappointed with his performance, saying he conceded victory to the Argentinean and was mystified at his lack of concentration.

"Everything went wrong," he said. "I haven't made so many errors in a match. I think it would have been nice to play myself today. I made too many mistakes."

Norman wasn't surprised with his victory, saying he was playing well enough to win the tournament.

"It is difficult to play Marc. You never know with him -- he is out of his mind sometimes, he's walking around talking to himself and then crashing his racket," Norman said.

"Then all of a sudden, he'll make an ace so you've got to stay focused because you never know what will happen."