The fourth-seeded Wimbledon runner-up, MaliVai Washington, also slowed by an injury he suffered in winning a Davis Cup singles match against Brazil, lost 7-6, 6-3 to the 108th-ranked Argentinian, Javier Frana.
In other second-round upsets, Germany's Alex Radulescu beat the sixth seed Jason Stoltenberg of Australia, Armenia's Sargis Sargsian removed the ninth-seeded American Alex O'Brien, Guillaume Raoux, of France, knocked out the 14th seed, Mark Woodforde of Australia, and Jeff Tarango beat the 16th-seeded fellow American Vince Spadea. All the seeded players had received first-round byes and were seeing their first action of the tournament.
Todd Martin, twice the champion and the third seed, did progress, however, by overcoming the American qualifier Bryan Shelton 6-4, 6-4.
However, the performance of the 20-year-old Kuerten was the revelation of the night. The Brazilian drove in 18 aces, won 29 of 32 first-serve points and did not commit a single double fault.
"For me, this was pretty nice," Kuerten said. "One year ago I was sitting by my TV at home watching [Agassi] play."
Kuerten was also matching Agassi groundstroke for groundstroke and blasting winners past the Las Vegan even before Agassi sprained his already injured ankle in the second set. With the Brazilian leading 6-4, 3-1, the match was halted for around 10 minutes while Agassi's ankle was taped and examined, allowing him to continue.
Martina Hingis, the Australian Open champion, yesterday signed a three- year sponsorship deal with Opel, believed to be worth around pounds 300,000 a year - substantially less than the10-year deal with Steffi Graf which the company cancelled in 1995.
Results, Digest, page 25