John Isner moved on, while fifth-seeded Gilles Simon was knocked off Wednesday at the rain-shortened $1.3 million Citi Open tennis event.

Isner had his hands full with Alex Kuznetsov, but prevailed 7-6 (7-2), 7-6 (7-4) on the hardcourts at FitzGerald Tennis Center.

Simon felt the sting of defeat to Dmitry Tursunov, as the Russian claimed a 6-4, 6-2 victory.

Mardy Fish kept the dream of a U.S. champion alive by taking down 12- seed Julien Benneteau 6-3, 7-5.

Third-seeded Tommy Haas had his match with Tim Smyczek interrupted by the downpours. Haas dropped the opening set, 3-6, before recovering to win the second 7-5 and led 1-0 in the third when play was finally halted.

Kevin Anderson, the seven-seed, was on the verge of moving on, leading James Duckworth 6-3, 3-6, 5-4.

Top seed Juan Martin del Potro never got to see the court, with his planned match against Ryan Harrison set to be the marquee contest Wednesday night. The other match shelved due to weather was Jack Sock and Kei Nishikori.

Tenth-seeded French left-hander Michael Llodra was promptly sent packing by Czech veteran and 2011 D.C. champion Radek Stepanek, 6-2, 6-1, on Day 3.

In other completed matches, Ivan Dodig needed three sets to dispatch Tobias Kamke, 2-6, 6-2, 6-3.

The 2013 Citi Open champ will collect $292,200.