Petit, who had nine strikeouts throughout, retired his 46th consecutive batter after ousting the first eight Colorado hitters at AT&T Park in San Francisco.
The mark eclipsed Mark Buehrle's effort of 45, which was set back in 2009 during his time with the Chicago White Sox.
On a collective note, San Francisco's victory was their third on the bounce after Pablo Sandoval, Gregor Blanco and Angel Pagan all scored runs.
The Giants are four-and-a-half games adrift of National League West division leaders the Los Angeles Dodgers, who were not in action on Thursday.
Baltimore were also triumphant after prevailing 5-4 over the Tampa Bay Rays.
J.J. Hardy singled for the tie-breaking run as the Orioles ended their four-game series with three wins against the Rays.
The Orioles enjoy a seven-game buffer in the American League East after the New York Yankees were beaten 3-2 by the Detroit Tigers.
Alex Avila's at-bat helped the Tigers to victory in the ninth inning.
In other results, the Cincinnati Reds crushed the Chicago Cubs 7-3. Cincinnati had six steals in the first four innings, while Dylan Axelrod had eight strikeouts for the Reds.
The Atlanta Braves crushed the New York Mets 6-1, Braves pitcher Minor had a two-hit shutout and a RBI single in the second inning.
"It was fun to have a night like this hitting and pitching," he said.
Elsewhere, the Minnesota Twins blitzed the Kansas City Royals 11-5 and the Houston Astros were 4-2 winners over the Texas Rangers.
Jason Kipnis and Michael Brantley each singled, while Carlos Carrasco struck out seven as the Cleveland Indians beat the Chicago White Sox 3-2.
Meanwhile, Oakland Athletics lost 4-3 to the Los Angeles Angels.