Myers tossed a nine-hitter for his first shutout in four years and Philadelphia beat Washington 4-0 on Wednesday night, handling the Nationals their 12th straight loss.
"I think it definitely shows he's strong and capable of throwing about 120 pitches," Philadelphia manager Charlie Manuel said.
Myers (6-10) struck out nine and walked one in his sixth start since being recalled from the minors on July 20. He earned his first shutout since a 4-0 win over the Los Angeles Dodgers on May 20, 2004, and his first complete game since he tossed a six-hitter in a 6-2 victory against the Chicago Cubs on Sept. 20, 2006.
It was the third complete game this season for the Phillies, who stayed 1 1/2 games back of the NL East-leading New York Mets.
"Actually, I didn't think my fastball and location were that great at all," Myers said. "I thought I had a pretty good curveball."
Since being recalled from the minors, Myers is 3-1 with a 1.94 ERA.
"I think he's definitely capable of pitching like he did tonight," Manuel said. "We always have high expectations for Brett."
The Nationals tied the Kansas City Royals for the longest losing streak in the majors this season. The skid is the franchise's longest since the Montreal Expos dropped 12 straight from Aug. 13-27, 1976.
Ronnie Belliard collected two more hits for Washington, which has the worst record in the majors at 44-83. Belliard is batting .444 (24-for-54) this month.
The Nationals have been shut out 19 times this season.
"We're just not capitalizing right now," manager Manny Acta said. "That's what we've been doing lately."
"I got my adrenaline flowing around the eighth inning and the defense played great behind me," Myers said.
The Phillies took a 1-0 lead in the third without registering a hit. With runners on first and second and one out, second baseman Emilio Bonifacio fielded Jimmy Rollins' sharp grounder and threw to newly acquired shortstop Anderson Hernandez at second. Hernandez then made an errant throw to first trying to complete the double play, allowing Chris Coste to score.
The Nationals got Hernandez on Wednesday to complete the trade that sent reliever Luis Ayala to the New York Mets.
Balester gave up four runs, three earned, and seven hits in six innings.
"The toughest thing for me is to keep the ball down more consistently," Balester said. "It's not a maybe thing. You've got to do it. I've got to work on that because it's killing me."
Cole Hamels has Philadelphia's other two complete games this season. ... Orlando Magic guard Jameer Nelson, a former star at nearby Saint Joseph's University, threw out the first pitch. ... The game drew a sellout crowd of 45,166, the 16th in a row and the 42nd this season at Citizens Bank Park.