Philadelphia's Roy Halladay struck out nine to defeat Florida for the fourth time this season, and the surging Phillies extended their lead in the NL East to three games by beating the Marlins 10-5 on Wednesday night.

Halladay (19-10) gave up three runs and 10 hits in six innings for the Phillies, who swept a three-game series at Florida for the second time this season and are 17-3 away from home since Aug. 1. Halladay has a career-high 210 strikeouts, 41 coming against the Marlins, and is the Phillies' first 19-game winner since John Denny in 1983.

The win, combined with Atlanta's 4-2 loss to Washington, gave the two-time defending NL champions their largest division lead since May 25. Philadelphia trailed the Braves by seven games on July 21, and has gone 38-15 since.

Raul Ibanez and Wilson Valdez both had three hits for Philadelphia, and Chase Utley hit his 15th home run. Shane Victorino added two hits, his seventh multi-hit game in his last nine, and Jose Contreras — who relieved an ineffective Brad Lidge in the ninth — escaped a bases-loaded, one-out jam for his fourth save in five chances.

Logan Morrison had two hits for Florida, stretching his streak of reaching base to 35 straight games, the third-longest run in the majors this season.

Gaby Sanchez homered and scored twice for the Marlins, who used six pitchers, all relievers.

Jorge Sosa (2-3), making his first start since July 27, 2007, gave up six hits and six runs, four earned, in 2 1-3 innings. He threw 68 pitches, 46 more than his average in 15 previous relief appearances this year.

The Marlins went with the all-bullpen approach because they are simply out of starters.

The Phillies have an abundance, starting with Halladay.

Philadelphia went 8-1 at Florida this season, and the Marlins are surely pleased that they won't have to see Halladay — who pitched a perfect game against them on May 29 — again until 2011.

Halladay went 4-1 against the Marlins this season with a 1.66 ERA in 38 innings.

He's the third starter to win at Florida three times in a year, joining the Phillies' Jamie Moyer and the New York Mets' Oliver Perez, both of whom went 3-0 at the Marlins' ballpark in 2008. Halladay is the third starter to beat Florida four times in a season; Moyer (2007 and 2008) and Tom Glavine (2002) are the others.

By the time Halladay went to work, he had a 3-0 lead.

Jayson Werth lofted a two-out RBI single to right field to start the scoring, and Ibanez followed with a well-placed two-run double that just evaded the dive of Marlins center fielder Emilio Bonifacio. The Phillies took control with three runs in the third, a rally sparked by Utley's homer leading off the inning.

Down by six, the Marlins loaded the bases with one out against Lidge in the ninth and put the Phillies' bullpen to work, as J.C. Romero and Contreras both began warming.

Lidge's night ended when he walked Sanchez to force in Bonifacio. Contreas struck out Chad Tracy, then retired Scott Cousins on a ground ball to second to finish the sweep.

NOTES: Marlins RF Mike Stanton got the night off after going 0 for 4 with four strikeouts Tuesday night, dropping the rookie's average to .247. He's hitting .150 at Sun Life Stadium, and was on deck when the game ended. ... Phillies C Carlos Ruiz had two hits, giving him a .364 average in 16 games against Florida this season. ... The Phillies, 41-34 outside Philadelphia, are assured of a winning road record. ... Philadelphia's last 20-game winner was Steve Carlton, who won 23 in 1982.