Roy Oswalt continued his dominance over NL West teams with a four-hitter, Ivan Rodriguez homered among his four hits and Miguel Tejada also connected, leading the Houston Astros to an 8-1 victory over the Los Angeles Dodgers on Friday night.

Oswalt (6-4) threw 105 pitches on six days' rest en route to his 16th complete game in 261 career starts and third this season. He struck out five and walked none. Oswalt is 12-0 with a 2.13 ERA in his last 13 starts against the NL West, and is 36-12 against that division during his career.

The Astros, who were a season-worst nine games out of first place on May 31, are three games behind NL Central-leading St. Louis following their 14th win in 20 games. Since May 29, they are 28-16, while the Dodgers are 22-19. But Los Angeles still owns the best record in the majors at 56-33, with a 6 1/2 game lead over San Francisco.

First baseman Lance Berkman, who leads Houston with 18 homers, didn't start because of a mild strain of his left calf. But the Astros staked Oswalt to an early 7-0 lead and won for the seventh time in their last nine games at Dodger Stadium.

Dodgers manager Joe Torre, whose relief corps has pitched a major league-high 312 1-3 innings, was forced to go to his bullpen with two outs in the second after Chad Billingsley (9-5) gave up hits to nine of the 14 batters he faced and left with a 6-0 deficit. The All-Star right-hander is 0-2 with a 6.55 ERA in six starts since beating the Texas Rangers on June 14 at Arlington.

In his previous start against the Astros on April 23 at Houston, Billingsley pitched 7 1-3 innings of three-hit ball. But in the rematch, he threw 33 of his 52 pitches in the first inning while giving up four runs on six consecutive two-out hits.

Tejada homered to left-center with two out for his eighth of the season. Hunter Pence added a two-run double and Rodriguez singled home the fourth run. The Dodgers came into the game having outscored their opponents 70-29 in the opening inning.

Geoff Blum, who came in 2 for 17 with no RBIs against Billingsley, knocked him out of the game with a two-run double, and Rodriguez led off the third against Jeff Weaver with his eighth homer to make it 7-0.

Rogriguez needs four home runs to become the seventh player in history to hit 300 homers as a catcher. The 14-time All-Star has 303 overall.

The Dodgers, who have totaled just nine runs in their last seven home games, scored in the third when right fielder Hunter Peace lost Orlando Hudson's towering flyball in the twilight for a triple and Russell Martin drove him in with a groundout.

NOTES: The Dodgers are 15-15 at home since their record-setting 13-0 start. ... Astros RHP Chris Sampson was placed on the 15-day disabled list, retroactive to July 10, because of muscle spasms in his shoulder. The move enabled him to return to Houston, where his wife Heather is about to give birth. RHP Chad Paronto was recalled from Triple-A Round Rock and is expected to join the club on Saturday. ... Ramirez is 12 for 37 with three homers and nine RBIs in 11 games since returning from his 50-game drug suspension on July 3, and the Dodgers are 6-5. ... Darin Erstad made his 12th start of the season and sixth at 1B. The 14-year veteran, who is the only player in major league history to win a Gold Glove as an outfielder and an infielder, has played in 177 consecutive games on defense without an error since May 22, 2007 _ when he was playing RF.