"Baseball's kind of a strange game," Zito said. "I actually felt better tonight than I did my first two games."
Betancourt's fifth career grand slam highlighted the seven-hit inning that chased Zito, who hadn't lost since last August against the New York Mets. Rickie Weeks doubled home two runs and Jonathan Lucroy added a two-run single as the Brewers sent 12 batters to the plate. Zito faced 11 of them.
"I have to tip my cap to them for hitting my pitches," Zito said. "It was a great streak that mattered most in the playoffs. So, it's something I'll always take great pride in."
Zito pitched 7 2/3 scoreless innings with one walk and six strikeouts in Game 5 of the NLCS at St. Louis, which the Giants won 5-0 to stave off elimination. The Giants won all three of his starts in the postseason.
Zito (2-1) had opened the season with consecutive scoreless seven-inning games. He struck out five and walked two in 2 2/3 innings and his 0.00 ERA ballooned to 4.86 ERA. Dating to last season, the Giants had won the previous 13 regular-season games started by Zito.
Giants manager Bruce Bochy thought that Zito threw the ball well, despite the loss.
"A changeup up for a grand slam was the difference in the game," he said. "It was tremendous what he did on that streak he was on."
Gomez's home run off the foul pole in left snapped Zito's scoreless streak to start the season at 15 2/3 innings. Zito is 0-5 in eight starts at Miller Park and has never lasted more than 5 2/3 innings.
Brandon Kintzler (2-0) got the win in relief for the Brewers.
Brewers manager Ron Roenicke was glad that his offense has shown some life the last two games after struggling for so long.
"It sure was nice to see us scoring all those runs," he said. "Another big inning. That seems to be us. We seem to be big innings and not consistent through a game, but I'll certainly take that."
The Brewers snapped a 32-inning scoreless streak in Sunday's 4-3 win against the St. Louis Cardinals in 10 innings.
Wily Peralta started for Milwaukee and gave up three runs, two earned, in the third inning, and then left in the fifth with bases loaded and nobody out. He went four innings, allowed six runs, five earned, on seven hits with three walks and a strikeout in his first career start against the Giants.
In the fifth, Peralta, who the Brewers are counting on to be a reliable third starter, gave up Sandoval's run-scoring single and then left the bases loaded and no outs for Mike Fiers. He got the first out, but then allowed Belt's sacrifice fly. Gregor Blanco lined out to right to end the threat.
Roenicke thought that Peralta's power pitching disappeared.
"He lost velocity in the fourth inning. He lost velocity in the fifth inning," Roenicke said. "He gets out of rhythm. He starts aiming the ball. The fastball doesn't have the same life on it."
Trying to protect a three-run lead, Fiers left the bases loaded with one out in the sixth. Kintzler came on and gave up a sacrifice fly to Sandoval, but then struck out Buster Posey to end the top of the sixth.
Brandon Crawford hit his second home run of the season, a solo shot, in the fourth.
The Giants are going to call up right-hander Jean Machi from Triple-A Fresno on Wednesday. LHP Jeremy Affeldt is going on the 15-day disabled list with a right oblique strain. ... Brewers pitcher Yovani Gallardo was arrested on a drunken-driving charge Tuesday after authorities said he was driving on a city highway with a blood-alcohol content nearly three times the legal limit. He pitches Thursday in the final of the three-game series with the Giants. ... The Giants and Brewers held a moment of silence for the victims of the tragedy at the Boston Marathon. ... Giants and Brewers players, managers and coaches wore uniform No. 42 in honor of Jackie Robinson. ... Ryan Braun struck out four times. ... The Brewers improved to 2-5 at home. The other win came on opening say when they beat the Colorado Rockies 5-4 in 10 innings.