WASHINGTON — Mardy Fish passed on the London Olympics. Tommy Haas wanted in.

The top-seeded American required big and timely serves to reach the second round. The fourth-seeded Haas advanced with relative ease.

Fish rallied from an opening-set loss and beat Bjorn Phau 4-6, 6-1, 6-2 on Tuesday night in the Citi Open.

Haas, an Olympic medalist denied a chance for a second, continued his impressive summer by defeating American qualifier Michael Russell 6-4, 6-2.

No. 8 Sam Querrey survived three tiebreakers to beat Igor Andreev 7-6 (7-2), 6-7 (2-7), 7-6 (7-2).

Fish, the 2004 Olympic silver medalist in Athens, entered this week on a gimpy right ankle, one he injured two weeks ago in Atlanta. He then tweaked the injury diving for a ball late in the first set.

"It's 75 percent, but not hampering me in a bad way," Fish said.