KEY BISCAYNE, Fla. -- Defending champion Andre Agassi continued his steady march towards a record fifth Nasdaq-100 Open title with a 6-3 7-5 quarter-final win over Ecuador's Nicolas Lapentti.

Next up for the American is Chile's Marcelo Rios, who advanced with an impressive 7-6 (7-0), 6-2 victory over Argentina's Juan Ignacio Chela.

Their quarterfinal had an atmosphere more akin to a South American soccer game rather than a tennis match as supporters of the players sang, chanted and waved flags.

But it was Rios, displaying some of the dazzling form that carried him briefly to the world No. 1 ranking in 1998, who came out on top.

"I'm looking forward to it," said ninth seed Agassi, who has lost in both of his meetings vs. Rios, including the 1998 Nasdaq final.

"This is where we played in the finals and I have strong memories of that. He seems like he's playing a lot better now and that's good," Agassi said. "He certainly has a lot of talent but I feel ready. I really don't know what to expect. He strikes the ball as well as anybody."

After losing his opening match at Indian Wells last week, Agassi has been in sublime form on the Nasdaq hard-courts, easing his way into the semifinals without dropping a set.

After taking the first set, Agassi twice broke the 20th seed from Ecuador in the second and looked in control.

Lapentti broke back both times, but when Agassi broke a third time to go 6-5 in front, he could not respond.

"He constantly has you having to adjust," said the American. "I managed to close it out, but it was hard-fought all the way."

Sixth seed Marat Safin of Russia booked his place in the quarterfinals, easing past Chilean qualifier Fernando Gonzalez 6-3, 6-3 to set up a meeting with world No. 1 Lleyton Hewitt.

Hewitt needed two days to book his place in the final eight, finally finishing off American James Blake 6-4, 6-1 in a rain-interrupted match Wednesday.

Unbeaten on American soil since winning the U.S. Open last year, Hewitt was well on his way to extending the streak to 21 matches when torrential rain stopped the match late Tuesday afternoon with the Australian leading 6-4, 3-1.

Picking up where he left off, Hewitt quickly went to work under a sizzling Miami sun, breaking Blake to go ahead 4-1 and then taking the last two games.

"It's always tough for both players," Hewitt said. "But you'd rather be a set and a break up than a set and a break down going overnight.

"But I came out and felt like I got better and better as the match went on." .