Werth hit his fourth home run in three games, and Howard added a mammoth three-run shot to support Blanton's eight effective innings and lead the Philadelphia Phillies to a 12-3 romp over the Arizona Diamondbacks and a three-game sweep.
Carlos Ruiz homered for the Phillies, who won their fourth straight game and eighth of nine.
The Phillies capitalized on Arizona starter Doug Davis' erratic location, scoring six runs -- five earned -- in five innings. Werth's two-run shot to center in the fifth gave Philadelphia a three-run lead, and Ruiz and Howard homered off different relievers during a five-run sixth.
"There's nobody in that lineup that's an out," Davis said. "They're relentless. The pitching wasn't that bad, but when you're hot, you're hot."
How hot? Philadelphia, which leads the National League with 171 home runs, have hit at least one in 10 straight games, and 28 in its previous 15. The 2006 team hit a franchise-best 216 in 2006, led by Howard's 58, also a team single-season record.
Every Phillies starter had at least one hit, except third baseman Pedro Feliz. Blanton had two singles, the first multihit game of his career, to become the third straight Phillies pitcher to record two hits in a game. Jamie Moyer and Cliff Lee did it Tuesday and Wednesday, respectively.
"I don't know," Blanton said with a shrug. "Hitting is contagious, I guess. Even for pitchers."
Blanton (8-6) picked up his second career RBI with a fourth-inning groundout. For once, he benefited from the offensive barrage. Despite heading into Wednesday with a 2.17 ERA in his previous nine starts, the right-hander had only three runs to show for it. He allowed a season-high 10 hits, but limited Arizona to three runs.
Philadelphia pitchers have an ERA of 1.94 in the last eight games.
After Chad Tracy's fourth-inning single tied it, Blanton retired 15 of his final 17 batters. Blanton said his game plan started working.
"I just stuck with it," he said. "And the balls started finding people. It's not an easy game, but when you get runs, you can attack the zone and make them beat you. It can be a lot easier."
Philadelphia scored three first-inning runs off Davis (7-11), highlighted by Ben Francisco's two-out single. The Diamondbacks scored a run in the second, and two runs in the fourth.
With Blanton working efficiently even while getting hit, he kept the Phillies in the game long enough for the offense to do the rest.
"He's a bulldog who comes right after you," manager Charlie Manuel said. "Tonight, he was very good."
Howard's shot reached the visitor's bullpen in center field for his sixth homer and 16th RBI in seven games. Werth continued what has been a career season with 28 homers and 76 RBIs.
"They come in bunches," Werth said. "Sometimes you feel good and your swing is good. But sometimes the opposite side of the coin is true, too. You take while you can get it and hold onto it as long as you can."
The Diamondbacks, who have lost five straight, didn't walk in the series and scored five runs.
"Today was a tough day, and it was a tough series," Arizona manager A.J. Hinch said. "We got dominated in three straight games. They hit the long ball and do a lot of damage. They're a good baseball team, that's widely known. They're the best team I've seen this season."
Ruiz's home run gave him a career-high seven. ... Blanton has not allowed a stolen base in his last 10 starts, and has only issued four walks in his previous 51 innings. ... Howard has six hits in his previous 12 at-bats vs. left-handed pitchers, including three doubles and a home run. ... Members of the Orlando Magic took batting practice at Citizens Bank Park before Thursday's game, as part of an annual team-bonding event hosted by guard Jameer Nelson, a Chester, Pa., native and former Saint Joseph's University star. Nelson was the only player to hit a home run. ... RF Justin Upton (right oblique strain) ran the bases and took fly balls in the outfield before the game. The team is targeting Monday for Upton to being a rehab stint, with Class A Visalia.