Pam Shriver, completing what she called "the best week of my tennis life," defeated Zina Garrison, 6-4, 6-1, yesterday in the final of the $280,000 Canadian Open in Toronto.

Shriver, of Lutherville, Md., collected $50,000 for winning the tournament, her third title of 1987.

Shriver, the third seed, set up her victory with a convincing 6-4, 6-1 semifinal win Saturday over top seeded Chris Evert. It was Shriver's first career triumph over Evert after 18 losses, dating back to 1978.

The 6-foot Shriver has reached the final of seven of 12 tournaments she's played in this year.

Shriver had not played in this tournament since she lost in the 1981 semifinal to Tracy Austin, then ranked No. 2 in the world.

After her victory, Austin showed a little too much jubilation for Shriver's liking and when the two came to the net to shake hands Shriver fired a string of obscenities at Austin.

"It took me six years to come back to this tournament, where I had one of my most infamous moments," said Shriver. "I had a loud mouth. I vowed this time I'd just keep my mouth shut and play good tennis, and look what it did."

ATP Championship: At Mason, Ohio, Stefan Edberg needed just 80 minutes to beat Boris Becker, 6-4, 6-1, and win the $375,000 first prize at the Jack Nicklaus Sports Center.

Edberg, of Sweden, the No. 2 seed, earned $48,000 for his fourth singles title this year. He lost serve just once in the match.

"I played one of my best matches ever," Edberg said. "Maybe the best one, it's hard to say. I felt really good out there right from the beginning."

Becker, of West Germany, the third seed, was unable to deal with Edberg's mix of volleys, topspin lobs, and serves. It was the second time in two weeks Becker has lost to Edberg, who took a 6-2, 6-4 win over the two-time Wimbledon champion last weekend in the semifinals of the Canadian Open in Montreal to end a seven-match losing streak against Becker.