NEW YORK, DEC. 4 -- Top-seeded Ivan Lendl and No. 3 Mats Wilander clinched semifinals berths with victories at the Masters tennis championship tonight.

Second-seeded Stefan Edberg also made the semifinals of the round-robin tournament when fellow Swede Wilander defeated No. 7 Pat Cash of Australia in the opening match at Madison Square Garden.

But No. 5 Boris Becker's chances of reaching the semis were severely damaged when No. 8 Brad Gilbert beat him for the third straight time.

The only way Becker can advance to Sunday's semifinals is to beat Lendl in straight sets in the final round-robin session Saturday. If he doesn't, Gilbert will gain the last semifinal berth.

In the first match Friday night, Wilander beat Cash, 7-6 (7-3), 6-3.

Lendl won the next match when No. 4 Jimmy Connors retired because of illness after falling behind, 4-3, in the first set. Gilbert, who upset Becker at the U.S. Open, beat him in the Masters nightcap, 4-6, 6-4, 6-4.

Gilbert said his return of Becker's booming serve was the key to victory.

"I returned his first serves pretty good," Gilbert said. "He relies on his serve a lot, and when it's not working, he's in trouble against me."

Connors, who has been suffering from a cold and ear infection, already had lost his first two matches in the $500,000 tournament and had virtually no chance of making the semifinals.

"It's tough to play when you can't breathe," he said after the match. "I was talking to the trainers and doctors and they said after three days, your resistance is virtually non-existent."