Hamels improved to 4-0 in five career starts against Cincinnati, allowing five earned runs in 36 innings. Brad Lidge escaped a threat in the ninth inning for his eighth save in 10 chances.
Howard's ninth homer off Johnny Cueto (4-2) helped the Phillies end his streak of four straight wins. Slumping Jimmy Rollins doubled home a run, and Pedro Feliz had two hits.
The Reds have lost a season-high four straight because their depleted offense is in a rut, scoring only four runs in the last 28 innings. They wasted a scoring chance in the ninth.
Lidge has been a concern for the Phillies lately. The closer gave up runs in six of his last eight appearances, boosting his ERA to 8.31, highest in the bullpen. He allowed an infield single to Alex Gonzalez and walked Laynce Nix with one out in the ninth, then struck out Willy Taveras - in an 0-for-19 slump - and retired Hairston on a routine fly.
Howard led off the second inning with a homer. The Phillies went up 4-1 with three runs in the fifth, when Feliz and Rollins had doubles. Cueto had allowed only six runs in his last six starts, but struggled in his first career appearance against the Phillies.
The defending World Series champions arrived in Cincinnati looking to fix their rotation, which ranked last in the NL with a 6.35 ERA. Manager Charlie Manuel demoted struggling Chan Ho Park to the bullpen on Tuesday, replacing him with left-hander J.A. Happ.
The Reds opened the series unsure when they would have first baseman Joey Votto back in the lineup. Votto, the Reds' top batter at .366, had to leave two games over the weekend in San Diego because of dizziness. He had more tests on Tuesday, and more were scheduled for the next few days.
Notes: Howard moved ahead of Johnny Callison for ninth place on the Phillies' career list with his 186th homer. ... More than 500 fans brought their dogs to the game, part of a promotion by the Reds. The dogs sat in the stands along with the 18,449 fans. ... The Reds put long reliever Nick Masset on the DL with strained muscles in his left side. Masset hasn't pitched since May 10. RHP Ramon Ramirez was called up from Triple-A Louisville to fill his role.
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