Billy Butler's single broke a 2-2 tie and drove in Lorenzo Cain with the first of five sixth-inning runs that helped the Kansas City Royals to a 7-2 victory over the San Francisco Giants that evened the World Series at a game apiece. 

Butler's hit off Jean Machi drove in his second run of the night before Salvador Perez lined a two-run double to the left-center wall to make the score 5-2 and Omar Infante homered into the left-field bullpen off Hunter Strickland.

After Infante's homer, Strickland started screaming and got into a confrontation with Perez as he crossed the plate. The dugouts emptied, but no punches were thrown and Strickland was replaced by Jeremy Affeldt.

Ventura allowed two runs and eight hits in 5 1-3 innings and didn't get a decision for the third straight start in the postseason. Kelvin Herrera, one of Kansas City's 100 mph-throwing relievers, escaped a two-on, one-out jam in the sixth to pick up the win.

San Francisco starter Jake Peavy had retired 10 in a row on 28 pitches before Cain's soft single to center leading off the sixth. Peavy then walked Eric Hosmer, and Machi came in and left a fastball up to Butler, who lined it into left for the go-ahead run.

San Francisco tied a World Series record by using five pitchers in the sixth.

After the ceremonial first pitch from retired Royals star George Brett, Gregor Blanco drove Ventura's eighth pitch, a 98 mph fastball, into the Kansas City bullpen for his first home run since Sept. 22. It was the 10th home run by the opening batter of a Series game, the first since Boston's Johnny Damon in 2004.

Escobar reached on an infield hit leading off the bottom half, a hard one-hopper that popped out of the glove of shortstop Brandon Crawford, who tried for a backhand stop.

Escobar was caught stealing second by catcher Buster Posey, but Cain doubled with two outs, Hosmer walked and Butler bounced a single past the outstretched glove of a diving Crawford to tie the game 1-1, ending Kansas City's 0-for-17 slide with runners in scoring position dating to Game 2 of the AL Championship Series against Baltimore.

Making his first start since Oct. 11, Ventura showed the heat that made him the starting pitcher with the highest average velocity in the major leagues this year. He reached 100 mph on his first pitch to Posey in the first.

Infante pulled a double with one out in the second and scored with two outs for a 2-1 lead when Peavy left a first-pitch fastball over the plate and Escobar sliced an opposite-field double inside the right-field line.

Pablo Sandoval doubled leading off the fourth, a drive that bounced off the glove of Cain with his back to the plate near the center-field wall. Sandoval, who reached base for his 25th consecutive postseason game, scored when Belt hooked a one-out changeup into right field for another double that tied the game 2-2.

San Francisco put two on with one out in the sixth, and the Royals brought in Herrera, usually their seventh-inning man. He retired Belt on a flyout to left and then, throwing at up to 101 mph, got Michael Morse to ground to shortstop for a forceout.

San Francisco, which opened at home en route to titles in 2010 and 2012, was trying to become the first team to win the first two Series games on the road since the 1999 New York Yankees on the way to their sweep of Atlanta. Forty-two of 53 teams to take 2-0 leads went on to win the title, including nine straight since the 1996 Braves lost to the Yankees in six games.

Game 3 is Friday night in San Francisco. Jeremy Guthrie will be Kansas City's starting pitcher, while Tim Hudson will take the ball for the Giants. 

The Associated Press contributed to this report.