With 29 Aces, Isner Tops Tursunov in Washington Semifinal WASHINGTON - A couple of plastic sandwich bags filled with ice were resting on his left thigh, and some others were chilling his right knee, as an admittedly exhausted John Isner assessed how he's holding up after eight victories in 10 days. "My body doesn't feel great," Isner said, then paused and smiled. At the same time, nothing is wrong with me, besides just being a little tired and a little worn out. But that's what happens when you play well. The highest-ranked American man certainly has been doing that lately. Isner, who is ranked 20th and seeded eighth, set up his sternest test of late, earning a matchup against top-seeded and two-time champion Juan Martin del Potro in Sunday's Citi Open final. Taking control by breaking serve immediately after a rain delay, Isner hit 29 aces and beat unseeded Dmitry Tursunov 6-7 (7), 6-3, 6-4. Later, del Potro came out much stronger after his semifinal was interrupted for more than three hours by showers and he turned things around to beat third-seeded Tommy Haas 7-6 (4), 6-3 in a match that ended past midnight. "The rain, for sure, helped me to come back in this match," said the seventh-ranked del Potro, who hasn't dropped a set in three previous victories against Isner. Del Potro stretched his winning streak at the hard-court tuneup for the U.S. Open to 13 matches. He won Washington's tournament in 2008 and 2009, then skipped it the past three years. Trailing Haas 4-1 when a downpour came, 2009 U.S. Open champion del Potro won four games in a row. The rain delay's annoying. It bothers me a lot, actually," said Haas, who showed frustration at various moments by spiking, tossing or kicking his racket. Come back out there, and the momentum was really on my side, at least for the first set, I think. (If) it would have been mine, it would have been maybe a different match. But these are all the 'ifs' and 'buts' and not worth talking about. Still, Haas actually held two set points late in the first, one of which del Potro erased with a 117 mph second-serve ace, and the other with a volley winner. "He went for it," said Haas, a finalist last year. He deserved it. Because of all the delays, unseeded Andrea Petkovic's 7-5, 6-3 victory over No. 4 Alize Cornet in the second women's semifinal did not start until after 12:30 a.m. Sunday - and did not finish until after 2:10 a.m. Petkovic, seeking her first title since 2011, was scheduled to return to the court about 15 hours later to meet defending champion Magdalena Rybarikova in Sunday's final. Rybarikova beat Ekaterina Makarova 6-2, 6-0 in a semifinal stopped by rain at 5-2 in the first set. Much, much earlier, Isner finished with a flourish - his last six serves were aces - and continued the strong form he showed last week while winning the title at Atlanta on a hard court. "When you're winning, you're playing a lot of matches, and from that, naturally, you're just going to wear down," said Isner, who was visited by a trainer in the third set but said the left leg injury that forced him to stop playing at Wimbledon in June was not bothering him. "I just wanted to get it massaged a little bit," said Isner, who for years has been officially listed as being 6-foot-9 by the ATP, but the tour's website recently changed that to 6-10. It wasn't anything I was seriously worried about. Isner, the 2007 runner-up in Washington, acknowledged his body feels "like it's a little beat up" after a second consecutive three-setter and a busy 1½ weeks, "but I'll be ready to go tomorrow, for sure." After dropping the first set against Tursunov, Isner was ahead on serve 2-1 in the second when, with the match 70 minutes old and a drizzle falling, play was suspended. When they resumed at 30-40, Isner converted the break point with a forehand passing winner on a 12-stroke exchange. "It's definitely not a comfortable feeling" to return from a delay facing break point, Tursunov said. Really, you understand that if you don't win this point, you're down a break, and then the set is over. Indeed, that was the first break in the match, and all Isner would need to even things at a set apiece 15 minutes later. "Gave me all sorts of momentum," Isner said. He broke again to lead 3-2 in the third, this time at love, helped by three unforced errors by the 61st-ranked Tursunov. That was pretty much that, because Isner's powerful serve was clicking - just as it usually does during the summer hard-court season in North America. "It's my absolute favorite time of the year," said Isner, whose best Grand Slam showing was a run to the U.S. Open quarterfinals in 2011. It's not a coincidence that I play and do well here in the summer, every single year. Isner won 69 of 86 points he served Saturday, including runs of 16 and 14 in a row, and did not face a break point. You really can't see the serve too well. ... It's really just a lot of guessing," Tursunov said. Said del Potro, looking ahead to facing Isner: "Nobody can break his serve in this tournament. ... Of course, sometimes you get frustrated when you can't return his serve. If Isner wins Sunday, he would earn his third title of 2013 and pull even with No. 1 Novak Djokovic for the third-highest total on tour. Only Rafael Nadal (seven) and Andy Murray (four) have won more. As for whether a ninth match in 11 days might force him to reconsider his schedule over the coming weeks - the year's last major tournament starts in New York on Aug. 26 - Isner said he hasn't thought about that yet. "I want to be as fresh as I can for the U.S. Open," the 245-pound Isner said. I have played a lot of matches (and) I'm not necessarily built to play week after week after week.