MELBOURNE, JAN. 16 (MONDAY) -- Defending champion Mats Wilander survived a first-round scare at the Australian Open today, beating fellow Swede Tobias Svantesson, 6-3, 2-6, 7-5, 5-7, 6-3, in the opening match on Center Court. Wilander, who has struggled since taking over the No. 1 ranking at the U.S. Open last September, needed more than three hours to eliminate Svantesson, ranked 100th in the world. "I was not pleased with the way I played or approached the match, but I'm pleased with the way it turned out," Wilander said. In other opening-round matches, Jan Gunnarsson of Sweden upset sixth-seeded Henri Leconte of France, 6-4, 6-3, 6-2, No. 11 Thomas Muster of Austria beat American Joey Rive, 6-2, 6-2, 6-4, and No. 14 Jonas Svensson of Sweden downed Menno Oosting of Holland, 6-2, 6-0, 6-4. In women's play, sixth-seeded Zina Garrison of the United States defeated Maria Lindstrom of Sweden, 6-1, 6-3, and American Elise Burgin eliminated No. 11 Sylvia Hanika of West Germany, 6-3, 6-1. Shortly after Wilander's match ended, it started to rain and the retractable roof over the 15,000-seat stadium was closed. While play was halted on the outside courts, the featured matches on Center Court continued after a brief delay. Defending women's champion Steffi Graf was scheduled to play Kerry-Anne Guse of Australia in the stadium Monday night. Wilander went up a break in the sixth game of the final set when Svantesson made four consecutive unforced errors, and closed out the match with a love service game. "In the beginning, I didn't think it was going to be such a tough match," Wilander said. "But he played very well and served very well." Svantesson, playing Wilander for the first time, rallied from love-40 to win the fourth set on a running cross-court forehand. But Wilander, who won three of the four Grand Slam events last year, was not shaken. "I always felt I could win, that I could raise my game a little higher than he could," he said. Svantesson, a former Oklahoma State player, ran out of steam in the final set. "Maybe mentally I got a little drained," he said. Since beating Ivan Lendl in a marathon U.S. Open final, Wilander hasn't performed like the No. 1 player in the world. He failed to make the semifinals at the Masters, lost to Carl-Uwe Steeb in the Davis Cup final against West Germany and was beaten by John McEnroe in an exhibition match last week. "It was hard to motivate myself after the U.S. Open," Wilander said. "After that final, it didn't seem like anything else mattered very much." Gunnarsson, ranked 85th in the world, needed only 87 minutes to eliminate Leconte from the first Grand Slam event of the year. He served 11 aces, including three straight in the sixth game of the final set. It was the second week in a row that Leconte has lost to an unseeded Swede in the opening round. He was beaten by Peter Lundgren last week at the New South Wales Open in Sydney. "My concentration is not there," said Leconte, a finalist at last year's French Open. "I'm mentally tired. I need to stay off the court for about 10 days."