WASHINGTON (AP) -- It was a another good day for unseeded American John Isner at the Legg Mason Tennis Classic.
Isner, who was part of the University of Georgia's NCAA championship team in May and is playing in just his second ATP event, pulled another upset by beating No. 8 Benjamin Becker 3-6, 7-5, 7-6 (6).
On Tuesday, Isner advanced when Tim Henman double-faulted on match point, also in a third-set tiebreaker.
Isner will next play American Wayne Odesnik, who beat No. 10 Juan Martin Del Porto, 3-6, 7-6 (10), 6-3.
Mardy Fish and his knees need a break, but he knows it's the wrong time on the tennis calendar to try to take one.
Still bothered by tendinitis, Fish was knocked out in the second round of the Legg Mason, 7-6 (4), 6-4 by Michael Berrer.
After the match, Fish admitted that his left knee still wasn't healthy after he retired from a match last week in Indianapolis.
"It's pretty painful,'' Fish said. "It's just one of those thbeings that needs like a month off.''
But Fish, who missed most of 2005 because of a wrist injury, said he's not yet ready to skip important upcoming tournaments in Montreal and Cincinnati that lead into the US Open.
"I'm willing to try. I'm willing to put in the work,'' he said. "It's just one of those things that probably needs a little more than six days.''
Fish said the knee continues to bother him on his serve, which he struggled with throughout the match. He managed eight aces, but was also broken four times.
After losing the tiebreaker in the first set, Fish found himself down a break in the second, but managed to get back even at 3-all. However, he lost serve again to fall behind 5-4, and Berrer ended the first meeting between the two players by serving out the match in the next game.
Second-seeded Tommy Haas was strong enough to beat Colombia's Alejandro Falla 6-3, 6-2. It was the first match for Haas since Wimbledon, where he withdrew with a torn stomach muscle before a fourth-round match against Roger Federer.
Haas broke Falla three times in the second set to secure his place in the third round, where he will play American Michael Russell. He advanced after Wesley Whitehouse retired in the second set with Russell leading 7-6 (1), 4-1.
Former Australian Open champion Thomas Johansson also reached the third round by beating defending champion and No. 4 seed Arnaud Clement 1-6, 6-3, 6-4.
It was the first match on hard courts this summer for Clement since losing in the first round at Wimbledon.
Joining Berrer and Isner in the third round was No. 7 Ivo Karlovic, who made quick work of Russian Evgeny Korolev, 6-3, 6-3. The 6-foot-10 Croat got 64 percent of his first serves in, and finished the match with 18 aces. He also broke Korolev's serve three times, the final time to end the match.
Karlovic will play 12th-seeded American Vince Spadea, who beat South African Wesley Moodie 7-6 (5), 7-6 (3).
Radek Stepanek also reached the third round by beating American Paul Goldstein, a native of nearby Rockville, Md., 6-3, 4-6, 6-4. Up next for Stepanek is top-seeded Andy Roddick.