If not, San Francisco will have some company in the National League Wild Card race.
Zito will try to pitch his club to its second series victory over St. Louis this season in today's finale of a three-game set at Busch Stadium.
The 32-year-old lost his first four career decisions versus St. Louis before notching eight scoreless innings of three-hit ball in a 2-0 win over the Cards on April 24, setting a season high with 10 strikeouts.
That victory helped the Giants take two of three over the Cardinals at home after the clubs split four meetings in St. Louis a season ago to close out their 2009 season series.
Zito, though, hasn't won since July 16, going 0-3 with a 3.69 ERA in six outings since. He has yielded eight runs and 18 hits in his last two outings, getting a no-decision versus the Cubs on Aug. 11 before dropping a start in Philadelphia on Tuesday.
Zito is 8-7 with a 3.56 ERA this year, but 2-5 with a 4.50 ERA in 12 starts on the road.
Jaime Garcia draws the starting assignment for the Cardinals with the 24-year- old coming off a tough-luck loss to the Brewers on Tuesday. Garcia dropped a 3-2 decision even though all three runs allowed over six innings were unearned.
"I thought he was in some of his best form. I think he was outstanding," Cardinals manager Tony La Russa said of Garcia, who fell to 10-6 with a 2.58 ERA this year.
The southpaw, who also struck out six, has posted an excellent 1.76 ERA in 11 home starts this season, but has just a 4-3 mark to show for it.
Garcia faced the Giants for the first time in his career on April 23 and took a 4-1 loss, allowing four runs -- two earned -- over six innings.
The Giants took the opener of this set before losing last night, 5-1, for their fourth loss in six games. Tim Lincecum suffered his fourth straight loss and eighth of the season -- both career highs -- after allowing four runs on six hits over 5 1/3 innings.
"I felt [the Cardinals] came out a little better prepared," said Lincecum, who had won his first five starts versus St. Louis. "Obviously the result is not there, what people want to look for, but in my mind I feel I'm getting back."
The Giants remained a game back of the Phillies for the Wild Card spot despite the loss, though the Cardinals moved within a game of San Francisco in that race. The Giants are also still five back of the Padres for first place in the NL West, while the Cardinals, who halted a season-high five-game losing streak, pulled within 3 1/2 contests of the first-place Reds in the NL Central.
Chris Carpenter bested Lincecum with seven-plus innings of one-run, five-hit ball, while Randy Winn had a solo homer and Pedro Feliz knocked in two runs in just his second game with the club since being acquired from Houston.
"We just need to win ball games," Carpenter said. "Going against a guy like Lincecum, he's going to put up a tough night. It was just nice to go out and see our guys get some runs and enable us to win."