Chicago's Derrek Lee pats Neifi Perez on the head after Lee hit a three-run home run in the eighth inning Wednesday. Associated Press Photo.

Derrek Lee is in the midst of a torrid stretch at the plate. The fact it's helping the Chicago Cubs win makes it even better.

Lee hit a three-run homer and went 5-for-5, raising his major league-leading batting average to .380 and leading the Cubs to a 9-5 victory over the Los Angeles Dodgers on Wednesday night.

The 29-year-old first baseman tied Alex Rodriguez of the New York Yankees for the major league lead with his 17th homer, and his 50 RBIs are tops in the majors.

Just as important to Lee, his big night helped the Cubs extend their winning streak to a season-high six games. Chicago (27-24) is a season-high three games over .500 after sweeping a three-game series at Dodger Stadium for the first time since May 1995.

"It was a great night for the whole team," Lee said.

The Cubs were more interested in talking about Lee. He had four singles before his homer and is 17-for-29 (.586) with five homers and 11 RBIs in his last seven games.

"I've played with a lot of great players. This is the best streak I've ever seen," Cubs catcher Michael Barrett said, shaking his head.

Only one game into June, Lee is easily on pace to better the career highs of 32 homers and 98 RBIs he set last year. He went 8-for-15 in the series in Los Angeles.

"As hot as he is and as well as he's swinging the bat, if you mislocate pitches in the middle of the plate to this guy, you're going to pay for it," Dodgers manager Jim Tracy said. "When you lead in all offensive categories that would qualify you for the Triple Crown, it's very obvious that he's really beginning to find himself offensively."

Neifi Perez was 4-for-5 and hit a three-run homer, helping the Cubs win in left-hander John Koronka's major league debut. The 24-year-old Koronka (1-0) allowed three runs and six hits in five innings.

Derek Lowe (4-5), pitching on his 32nd birthday, yielded a season-high 13 hits and six runs in 5 2-3 innings. Los Angeles has lost 24 of 38 after a 12-2 start.

Brewers 5, Padres 2

At San Diego, Carlos Lee and Geoff Jenkins homered off ineffective Brian Lawrence (3-6), and the Brewers ended the Padres' club-record 11-game home winning streak.

Brady Clark singled in his first three at-bats and scored twice for the Brewers, who snapped their four-game losing streak. Jenkins had three RBIs and Damian Miller had three of Milwaukee's 15 hits.

Doug Davis (7-5) threw eight strong innings to win his third straight start.

Braves 5, Nationals 4

At Washington, Wilson Betemit hit a tying two-run homer off Hector Carrasco (1-1) and Marcus Giles capped an eighth-inning rally with an RBI single off T.J. Tucker.

John Smoltz (4-4) gave up four runs over seven innings on six hits, four walks and a wild pitch. Chris Reitsma got the final six outs for his second save.

Astros 4, Reds 1

At Houston, Oswalt took over the major league lead for victories against a team without a loss, improving to 14-0 against Cincinnati.

Oswalt (6-6) was tied for the lead in victories against one team without a loss with Pedro Martinez of the New York Mets, who is 13-0 against Seattle. Randy Johnson of the New York Yankees is 12-0 against the Cubs.

Lance Berkman put the Astros ahead 2-1 in the fourth inning with a homer off Ramon Ortiz (1-4).

Mets 2, Diamondbacks 1

At New York, Victor Zambrano (3-5) took a shutout into the ninth inning and Jose Reyes had three hits and three stolen bases.

Mike Piazza had an RBI double and Carlos Beltran drove in the first run with a groundout to help the Mets bounce back from consecutive defeats. Braden Looper got his 12th save.

Brandon Webb (6-2) took the loss despite allowing just one run in seven innings.

Pirates 9, Marlins 1

At Pittsburgh, Rob Mackowiak hit his second career grand slam and drove in five runs.

Josh Fogg (4-3) limited the Marlins to one run and five hits in six innings as the Pirates won their ninth in a row against the Marlins.

Phillies 10, Giants 6

At Philadelphia, pinch-hitter Chase Utley's two-out grand slam off LaTroy Hawkins (1-5) in the eighth inning helped the Phillies beat slumping San Francisco, which has lost six straight for the first time since August 2003.

Cardinals 8, Rockies 6

At Denver, Mark Grudzielanek had four hits and two RBIs, and Matt Morris (6-0) fought through six shaky innings to remain unbeaten for St. Louis.

St. Louis had 17 hits, with Grudzielanek finishing 4-for-5 and Scott Seabol 3-for-3 with two RBIs.