SAN FRANCISCO (AP) -- Pat Burrell hit a go-ahead solo homer in the eighth inning after an earlier two-run single, Aaron Rowand also homered and the San Francisco Giants beat the Chicago Cubs 5-4 on Wednesday night.
Burrell also made a perfect relay throw from left field that saved an early run for the Giants, who finish this series Wednesday before a weekend showdown with the first-place San Diego Padres.
San Francisco began the day 2½ games behind San Diego in the NL West.
Rowand's 10th homer of the year, which came in the sixth, gave him seven straight seasons with double-digit home runs.
Burrell has been quite an addition since joining the Giants on June 4. Over his last 15 games, he is batting .356 with 10 of his 16 hits going for extra bases. That includes three home runs. His eighth homer of the year leading off the eighth came off Justin Berg (0-1).
Sergio Romo (5-3) recorded five outs for the win, while All-Star closer Brian Wilson pitched the ninth for his 33rd save in 36 opportunities. Wilson entered the game tied with San Diego's Heath Bell for the major league lead in saves.
Blake DeWitt of the Cubs cut his upper lip when he crashed into Giants catcher Buster Posey in the second on the play started by Burrell on Welington Castillo's double. Castillo got a hit in his major league debut and first at-bat.
Giants starter Barry Zito gave up a season-high 10 hits in 6 1-3 innings. His winless stretch extended to five straight starts despite being staked to a 3-1 lead. The lefty has only one win in 11 starts since June 12, going 1-4 during that stretch with six no-decisions, including three straight.
This game marked only the third time during the stretch that the Giants backed the 2002 AL Cy Young Award winner with more than three runs.
Chicago starter Tom Gorzelanny allowed eight hits and four runs over six innings. He struck five but left with a no-decision for the second time in three winless starts following a season-high four-start winning streak.
The Cubs scratched third baseman Aramis Ramirez about an hour before the first pitch with a sore left ribcage. Jeff Baker started in his place.
The Giants acquired infielder Mike Fontenot from the Cubs before the game, so all Fontenot had to do was walk between the two clubhouses and switch uniforms. He was available off the bench for San Francisco.
Notes: Giants OF Andres Torres stole third for the sixth time this year, most in the NL. ... Chicago announced that LHP reliever John Grabow is done for the season. Already on the DL since June 29 with a sprained left knee, the pitcher tore the medial collateral ligament while on a rehab assignment in the Arizona League. He is scheduled to meet Monday with the team orthopedist in Chicago to discuss his options, and surgery is possible. The hope is that Grabow will be ready for the start of spring training 2011. He was 1-3 with a 7.36 ERA in 28 appearances this year. ... The Giants activated INF Eugenio Velez from the DL and optioned him to Triple-A Fresno. Velez was struck on the head July 25 by a foul ball while in the dugout against Arizona. ... The Cubs still don't know how long 1B Derrek Lee will stay on the bereavement list. He has been spending time with his ill grandfather in his native Sacramento and can't play before Friday.