SCOTTSDALE, Ariz. -- Andre Agassi put a stop to a string of upsets when he beat Greg Rusedski 6-4, 6-4 on Wednesday night in the Franklin Templeton Tennis Classic.

The win sends Agassi, a three-time Scottsdale champion and the event's top-seeded player, into a quarterfinals match Friday with Juan Ignacio Chela, one of the upstarts who eliminated a favorite earlier in the day.

"I felt pretty good," Agassi said. "I took care of my serve well, executed my shots well. I got off to an early break in each set, which always helps.

"You know, Greg's a dangerous player -- he doesn't give you a tremendous amount of rhythm, and he can go on long streaks where you don't even get a sniff of his serve."

Rusedski, whose serve has been clocked at an ATP-record 149 mph, never got close to that kind of velocity, but still served 10 aces.

But Agassi, whose loss to Lleyton Hewitt in the San Jose final Sunday kept him from his 50th career title, continued his masterful play to go 6-2 against Rusedski, including three straight wins since Rusedski beat him in the San Jose final last year.

Agassi fought off two break points after falling behind 15-40 in the 10th game of the second set.

He drew even with two forehands that tricked Rusedski into returns that wouldn't stay in and, after another deuce, finished the match with a service winner and an ace.

"It's just the one or two points in a match, and that's it," said Rusedski, who was broken in the first game of the second set and took a medical break to tape a blister on his left hand after the third. "If Andre doesn't win those two points at 15-40, it becomes an interesting match again."

Earlier, Noam Okun reached his first career quarterfinal by beating No. 6 Albert Portas 7-6 (4), 6-4, and Chela stunned No. 5 Alex Corretja 6-4, 7-5.

That left the tournament with Agassi, No. 3 Pete Sampras and No. 7 Xavier Malisse among the eight seeded starters.

Chela, a finalist in Sydney and a semifinalist the last two weeks in Buenos Aires and Acapulco, pushed his remarkable comeback one step further.

The 22-year-old Argentine was suspended for three months last year after testing positive for steroids in August 2000. His ATP entry system position dropped to 810th, but he finished 71st by winning six Challenger events.

"I had much determination," said Chela, who says he unknowingly received the steroids as prescription drugs. "I wanted to demonstrate that I don't need anything bad to play tennis."

Now, he's eyeing the top 40 after improving his singles record to 14-6 by ousting Corretja, No. 18 in the entry system.

Chela served eight of his 10 aces in the first set, then relied on smooth baseline play in the second. He broke Corretja and won the 11th game with two consecutive forehand winners.

"I think it's my confidence now, and maybe good luck," Chela said.

Corretja, who was married Dec. 1, acknowledged being rusty. He went to 1-2 after being knocked out in the first round of the Australian Open and the second in Scottsdale.

"I need more matches, of course, but the only way to play more matches is to play more tournaments," Corretja said.

Okun was 4-7 in ATP singles last season and 0-5 coming into Scottsdale this year and was the last player accepted into the tournament's main draw without qualifying.

But he virtually repeated his 7-6 (6), 6-4 win over Fernando Meligeni on Tuesday.

"Hopefully I can go on further in the tournament," Okun said. "I had a good win against Meligeni in the first round, and I played very well today."