MILWAUKEE (AP) -- Bill Hall spent the bus ride back from Wrigley Field watching video footage on a laptop computer and talking to teammates, eventually coming up with a subtle swing adjustment that paid off right away.
Hall homered twice and had a career-high six RBIs to help the Milwaukee Brewers beat the San Francisco Giants 13-4 in their home opener Friday. It was the third career two-homer game for Hall, who didn't hit a home run during spring training.
"I wasn't worried about not hitting home runs in spring training and exhibition games," Hall said. "I've never seen those stats on the back of anybody's baseball card."
The Brewers' bats seemed to all thaw out at once after taking two of three games from the Cubs in a chilly season-opening series.
"It was too cold in Chicago," said Rickie Weeks, who set a franchise record and tied a modern-day National League record by scoring a run in his 17th straight game dating to last season.
"Our fans have been hearing a lot about our team this spring, and I think, generated a lot of excitement," Yost said. "They had a good chance to see what they'll be rooting for all summer long."
The Giants, in their first season following the forced departure of Barry Bonds, have lost three of their first four games.
"We're not the type of team that can slug with the other clubs, especially this one," Giants manager Bruce Bochy said. "They can put a crooked number on the board, which they did quickly. It's important we do keep it close."
Carlos Villanueva (1-0) tied a career high with six strikeouts, going 5 1/3 innings. He held the Giants scoreless until the sixth, when he gave up two runs and Brian Shouse relieved. Villanueva was hoping to go deeper into the game, but managed to keep his frustration in check.
"It could have been a lot worse," Villanueva said. "Just sit down, calm down, and enjoy our offensive day."
Salomon Torres pitched three innings for his first save.
San Francisco starter Jonathan Sanchez (0-1) set a career high with eight strikeouts. But it wasn't much of a day otherwise for Sanchez, who gave up seven runs in four-plus innings. In two career starts at Miller Park, Sanchez has given up a total of 15 earned runs in six innings.
"I threw two [bad] pitches," Sanchez said. "It wasn't bad, but it'll get better."
Fielder's RBI single and Hall's homer put Milwaukee ahead 3-0 in the first.
In the Brewers' five-run fifth, Hall crushed his second homer of the game near the base of the steel tower where Milwaukee mascot "Bernie Brewer" glides down a slide to celebrate home runs.
Hall acknowledged the crowd with a curtain call -- then added an RBI single in the following inning as the Brewers put up another five runs.
Hall said it all went back to the adjustment he made after the watching video and talking to Fielder and Joe Dillon on the bus ride back from Chicago on Thursday. Hall figured out that his hands were getting too low when he cocked his body into the "launch" position as he prepared to swing.
"I saw what I was doing wrong, and I corrected it today," Hall said. "The results were pretty much immediate."
Tony Gwynn Jr. was out of the lineup as his tight left hamstring continues to have soreness. He wouldn't have started in center field anyway (Kapler filled that role), but Gwynn may be out longer.
"I'm trying to keep a positive mind-set about it," said Gwynn, who was expected to get extended playing time while Mike Cameron misses the first 25 games after being suspended for testing positive for a banned stimulant. "I'm trying to stay positive. Hopefully every day it'll get better and I won't be out too long."
Yost said he wasn't sure if Gwynn would need to go on the 15-day disabled list with the injury.
"I don't know, we're kind of taking it day-by-day," Yost said.
Gwynn left the game after the top of the sixth in a 6-3 loss Thursday to the Chicago Cubs. His first series to that point had been a success. Gwynn hit .571, drove in the game-winning run on Monday with a sacrifice fly and stole a base.
"My strength is good. They did some hamstring tests. My strength is really good, I'm just really sore for whatever reason," said Gwynn, who had a heat pack on the injury earlier in the day.
Gwynn, who battled a hamstring problem late last season while hitting .260 with 10 RBIs and eight stolen bases in 69 games, said the trainers told him there were no tears or holes in the hamstring.
According to the Elias Sports Bureau, the modern (since 1900) mark for most consecutive games with at least one run scored is 18, by the New York Yankees' Red Rolfe in 1939 and Cleveland's Kenny Lofton in 2000. ... Brewers catcher Jason Kendall scored his 900th career run in the sixth. ... Bochy on reliever Brad Hennessey, who gave up five runs in the sixth: "Henny is just not sharp with his stuff, his command. He'll make a couple of good pitches, but then he'll make a mistake."