The Giants had not gotten a hit since the second inning until Burks connected against David Weathers (3-4).
Brewer pitchers had retired 13 consecutive batters before Burks' 13th homer. Burks also had a two-run single.
Robb Nen got the final two outs for his 26th save and set a major league record for saves in July with 14, one shy of the record for any month.
Felix Rodriguez (4-1) pitched two hitless innings for the win.
At 19-8, the Giants tied their best record in July since moving west in 1958. They also finished 19-8 in 1994.
Geoff Jenkins hit a two-run homer in the fifth for the Brewers, tying the score at 3-3.
San Diego 4, Philadelphia 1--Woody Williams came within one out of his second shutout and Phil Nevin hit a two-run homer at San Diego.
Williams (6-3) was making his fifth start since coming off the disabled list because of an aneurysm under his right armpit. He gave up four hits and lost the shutout when Pat Burrell homered with two out in the ninth.
Williams struck out four and walked two to improve to 3-1 in his last four starts.
Nevin, who hit a game-winning ninth-inning homer Sunday against Pittsburgh, gave Williams all the support he would need with a two-run homer in the sixth against Bruce Chen (5-1).
St. Louis 4, Montreal 0--Darryl Kile pitched his first shutout in more than two years, and J.D. Drew and Fernando Tatis homered at Montreal.
Kile (13-6) got his eighth shutout and 23rd complete game as the Cardinals ended a four-game losing streak. Kile's last shutout came April 30, 1998, for Colorado against the New York Mets.
Kile gave up six hits and one walk, andstruck out six to join Garrett Stephenson as the only Cardinal to throw a shutout this season. He also drove in St. Louis' first run with a single in the second.
Chicago 2, Colorado 0--Kevin Tapani pitched 6 2/3 shutout innings and Mark Grace homered at Chicago as the Cubs won for the ninth time in 10 games.
Tapani (7-8) gave up four hits to improve his record against the Rockies to 6-0. He left in the seventh after giving up a single to Brian Hunter and a walk to Butch Huskey with two out.
Felix Heredia then retired Terry Shumpert on a pop-up to end the inning before Steve Rain and Rick Aguilera completed the four-hitter. Aguilera got his 24th save in 31 opportunities.
Houston 4, Florida 2--Jose Lima won his third consecutive decision and helped himself with a double before only 8,044 at Miami.
Lima (4-13) improved to 3-0 in his last five starts. He gave up eight hits in 6 1/3 innings, walking two and striking out three.
Octavio Dotel pitched 1 1/3 innings for his third save.