By Janie McCauley
The Associated Press

SAN JOSE, Calif. - Andre Agassi and Michael Chang have been playing each other since they were kids coming up in the junior ranks. In what might have been their final match, the two couldn't be at more different stages of their careers.

Agassi, fresh off his Australian Open victory, easily defeated Chang 6-4, 6-2 in the first round of the Siebel Open on Tuesday night.

Chang, who will retire after this year's U.S. Open, praised Agassi's tenacity, which once was a weakness.

"I think Andre knew tonight that if I had the opportunity to beat him, I would," Chang said. "Never once did he let his guard down."

The top-seeded Agassi, ranked No. 2 in the world, broke Chang's serve for a 5-4 lead in the first set and cruised through the second.

Agassi never gave up more than one point in a service game, hit nine aces to Chang's seven, and took advantage on Chang's second serve with his powerful return to win almost half of those points.

Agassi, a four-time champion here, is playing his first event since winning in Melbourne last month.

"I picked up where I left off, which is nice," said Agassi, who received some claps from 15-month-old son Jaden Gil, who watched briefly on the sideline with his mother, Steffi Graf.

"The first one is always a little unpredictable. There are times I come out after a Grand Slam win and feel like I can't miss. These days, I don't take a match for granted. I come here incredibly nervous."

Agassi improved to 14-7 in his career against Chang. They last faced each other in 1999 in Montreal.

"It's amazing," Agassi said. "It doesn't matter how long it's been since you've played, you look across the net and it's so familiar. ... For me, there are a lot of times I wish I didn't have to look at the ball and could watch him."

Chang won his first of 34 ATP titles in this tournament at age 16 in 1988, failing to drop a set through five matches. He won his only Grand Slam title at the French Open the following year.

The 30-year-old Chang, ranked 119th, played the first match of his farewell season and gave an inspired effort. He was the fan favorite from the beginning, and received a long standing ovation after the match.

"In my opinion, he's been one of the greatest competitors sports has ever seen," Agassi said. "Michael lays his heart on the line every time he's on the court."

Chang announced this will be his final season because he no longer believes he can compete at the highest level. He hadn't played a match in two months.

"Even though I lost this match, I can walk away feeling good," he said. "It's nice to know I can play against the guy, who of all players on tour is going to make me run the most. I can walk away today gaining some confidence."

Agassi will play Thursday against Mark Philippoussis, a 3-6, 6-3, 6-3 winner over Jean-Rene Lisnard.

Also Tuesday, Jan-Michael Gambill needed only 45 minutes to defeat qualifier Todd Reid, 6-2, 6-0. The fourth-seeded Gambill won 13 straight points to start the match, had seven aces and broke Reid's serve five times.

The 34th-ranked Gambill retired in his last two tournaments of 2002 with knee problems.

"This is the best I've started a year ever," he said.

Gambill, who reached the semifinals of this tournament the past two years, had 19 winners and committed 10 unforced errors to Reid's 17. More importantly to the 25-year-old Gambill, he hit 67 percent of his first serves in.