Mats Wilander received a confidence booster for next week's Australian Open when he toppled the world's No. 2 player, Ivan Lendl, to win the $100,000 Rio Challenge in Canberra, Australia. Wilander downed Lendl, 7-5, 7-6 (7-4) . . .

In Perth, Stefan Edberg gained the final of the West Australian open championships by beating Mike Bauer, 6-4, 6-7, 6-2. Edberg will meet Scott Davis in today's final.

Davis beat Steve Denton, 6-4, 7-6, in the other semifinal . . .

In Sydney, Martina Navratilova won her 13th tournament victory when she defeated Ann Henricksson, 6-1, 6-1, to take the $150,000 New South Wales women's open. Henricksson upset third-seeded Wendy Turnbull, 1-6, 7-5, 6-3, to gain the final.

Vitas Gerulaitis defeated Steve Meister, 7-6, 6-1, to earn a spot opposite Eliot Teltscher in today's final of the $200,000 South African Championship in Johannesburg.

The third-seeded Teltscher gained the final with a 6-2, 6-3 victory over Brad Gilbert as Americans took all semifinal berths . . .

In Rancho Mirage, Calif., Tom Gorman defeated Bob Lutz and Stan Smith downed Cliff Richey to advance to the final of the $40,000 Grand Champions tournament. The winner of today's final earns $8,000. Gorman beat Lutz, 7-6 (7-5), 6-3, then Smith ousted Richey, 6-3, 6-2, in semifinal matches.

All players in the tournament are 35 or over and have been on a Davis Cup team or have won a Grand Slam title.