WASHINGTON (AP)—John Isner became the second highly-seeded American to fall in two days, losing to Xavier Malisse, 6-4, 3-6, 7-6 (5) in the third round of the Legg Mason Tennis Classic on Thursday.

Also, third-seeded Fernando Verdasco defeated American Ryan Sweeting, 6-4, 7-5, and Tomas Berdych beat Andrey Golubev, 6-3, 5-7, 7-5. The matches followed a 4 1/2 -hour weather delay after storms hit the metro area in the afternoon.

Malisse overcame 18 aces by Isner and took advantage of a number of mistakes by his 6-foot-9 opponent, who had won each of his seven previous tiebreaks at this event.

“He serves well, and because of that you have a little more pressure on your serve,” Malisse said of Isner, who leads the ATP tour in aces. “I just tried to get the serve back. That’s his big weapon. You take what you can get, and right now I’m just happy to be in another quarterfinal.”

American Sam Querrey, the sixth seed, was ousted on Wednesday in straight sets by Janko Tipsarevic.

The weather delay might have affected the players.

“I don’t know, maybe,” Verdasco said. “Of course waiting is not an easy thing.”

Five more matches, including one featuring three-time tournament champion Andy Roddick and Gilles Simon, were scheduled to be played Thursday night.

The three doubles matches scheduled for earlier Thursday were pushed to Friday.