Courtesy of http://www.atpworldtour.com:

ATP World Tour No. 6 Juan Martin del Potro moved to within one win of defending his Legg Mason Tennis Classic title after defeating fourth seed Fernando Gonzalez 7-6(2), 6-3 Saturday in the semi-finals of the ATP World Tour 500 tennis tournament in Washington, D.C.  The Argentine will meet three-time Washington champion Andy Roddick, who took out fellow American John Isner 6-7,(3), 6-2, 7-5.

The second seed surrendered an early break lead in the first set but was reprieved as he hit back to take a one-set lead in the ensuing tie-break. The second set looked to have a more routine feel for del Potro as he broke twice to race into a 5-0 lead. The Argentine was briefly pegged back as Gonzalez recouped one of the breaks to reduce the deficit to 5-3, but del Potro did not falter at the second time of asking and served out the victory after two hours and six minutes.

The 20-year-old del Potro captured the Washington title last season in the midst of a 23-match winning streak that included four straight ATP World Tour titles at Stuttgart (d. Gasquet), Kitzbuhel (d. Melzer), Los Angeles (d. Roddick) and Washington (d. Troicki) before he reached the US Open quarter-finals (l. to Murray).

Del Potro is looking to become the first repeat winner in Washington since American Andre Agassi won back-to-back titles in 1998 and ’99.

The Tandil native will contest his seventh ATP World Tour final (5-1 record), after also finishing runner-up in Tokyo (l. to Berdych) in October 2008 and capturing his fifth trophy in Auckland (d. Querrey) at the start of 2009.

The No. 11-ranked Gonzalez was bidding to reach his second final in Washington, after finishing runner-up to Tim Henman in 2003. The 29-year-old Chilean won his 11th ATP World Tour title in his native country at Vina del Mar (d. Acasuso) earlier in the season and holds a 27-8 match record, having also reached the semi-finals at three further tour-level events.