Washington, Aug 7 (DPA) Andy Roddick claimed his 500th match victory with a defeat of American compatriot Sam Querrey 7-6 (4), 6-4 to reach the quarter-finals of the Legg Mason Tennis Classic.

The three-time champion, top-seeded at this edition, holds 27 career titles and, with Thursday's victory, improved to 27-4 in Washington.

He was only the fourth active player to reach 500 wins -- joining Roger Federer, Carlos Moya and Lleyton Hewitt.

Querrey came to Washington with the Los Angeles title in hand after playing two finals in preceeding weeks in Newport and Indianapolis.

'Sam's in form, having won in LA,' said World No. 5 Roddick. 'He had a month of good matches behind him. It was a tough win.