PHILADELPHIA -- The way things are going for the Philadelphia Phillies, it was only a matter of time before someone delivered a big hit.
The NL East-leading Phillies are on their longest winning streak in 18 years. They won 13 in a row from July 30 to Aug. 12, 1991.
"Everybody is just anticipating, waiting for it to happen because we have some big bats in our lineup," said pitcher Joe Blanton, who allowed one run in seven innings.
Jimmy Rollins homered and the Phillies relied on a strong pitching performance to pull out another win. Four relievers threw six hitless innings. Clay Condrey (6-2) tossed a perfect inning to earn the win.
Jeff Samardzija (0-1) retired the first two batters he faced in the 13th before walking Ryan Howard and Raul Ibanez. Werth then connected on a 1-1 pitch, launching his 21st homer into the seats in left. Werth circled the bases and stomped on home plate before getting mobbed by his teammates following his first career game-ending homer.
"It was a hanger and I was able to stay through it," Werth said. "I was just trying to have a good at-bat. I didn't need a homer. A single would've won it."
In a pitcher's duel between former Oakland teammates, Blanton and Rich Harden were outstanding. Blanton allowed five hits and struck out five. Harden gave up one run and four hits, striking out six in seven innings.
Blanton has been excellent since May 26, allowing three runs or less in nine of his 10 starts while lowering his ERA to 4.24 from 7.11. The right-hander is 4-1 with a 2.32 ERA in that span.
"I'm just trying to give us a chance," Blanton said.
Harden, who has struggled this season, has put together consecutive strong outings. He didn't allow an earned run in six innings against Washington last Thursday. Harden has lowered his ERA to a career-high 4.76.
Pitching isn't the problem for the Cubs, who won six of seven before coming to Philly. Chicago has scored the third-fewest runs in the National League.
"We're challenged offensively," Cubs manager Lou Piniella said. "You don't score runs, you don't win no matter how good you pitch. I'll tell you what. We might need a couple of hitters at the [trade] deadline."
Rollins gave the Phillies a 1-0 lead when he crushed a 3-0 pitch into the seats in right leading off the bottom of the third. Rollins, the 2007 NL MVP, has raised his average to .238 by hitting .424 (28 for 66) since going 0 for 28.
Harden didn't allow a hit after Rollins' homer until Werth singled in the seventh. Werth advanced to second on a sacrifice and third on a groundout, but Harden whizzed a 96 mph fastball past pinch-hitter Greg Dobbs to end the inning.
Phillies RHP Brett Myers, who had hip surgery in June, is ahead of schedule in his recovery and expects to return next month as a reliever. "You could tell he was determined to put a lot of work into it and get back to where he can pitch this season," Phillies manager Charlie Manuel said. Myers had 21 saves in 2007 in the only season he pitched out of the bullpen. ... Cubs RHP Ryan Dempster, on the DL since July 7 with a broken toe, could rejoin the starting rotation as early as next Thursday, according to Piniella. ... RHP Tyler Walker, who was designated for assignment by the Phillies last week, was outrighted to Triple-A Lehigh Valley. ... Piniella said RF Milton Bradley should return to the lineup Wednesday after taking a few days off to work on his hitting. Bradley grounded out as a pinch-hitter. ... Philadelphia's Chan Ho Park had five strikeouts in three perfect innings in relief.