Displaying his looping yet effective swing, Belt clobbered a pair of homers, including his first career grand slam that erased San Diego's 4-1 lead in the sixth inning. But the Padres scored three runs in the seventh to deal the Giants their fourth defeat in the season's first five games.
Belt certainly seemed tension-free as he cleared the right-field wall off Padres starter Luis Perdomo in the sixth inning and left-hander Ryan Buchter in the eighth.
"It's just a matter of getting a good pitch to hit and putting the bat on the ball," said Belt, who has three homers in San Francisco's last three games. "So far they've made some pretty good pitches on me, but I've stuck with my approach, and it's worked out. My goal right now is not to guess, not to sit too much on one pitch. I just want to see the ball because if I can do that, my hands will go where they need to go."
Statcast™ proves that Belt wasn't simply making empty boasts. He has demonstrated that he knows how to put a swing on the ball that will propel it great distances.
Belt's first home run of the season, which he hit Wednesday at Phoenix's Chase Field, was struck at a 30-degree launch angle, according to Statcast™. Belt led the Major Leagues in average launch angle with a 20.2 figure last year. Through the previous two years, Belt was tied with Chicago Cubs star Kris Bryant for the highest launch angle on homers (minimum 25 hit).
Belt's homers Friday were two of the most ferocious clouts of his career. The grand slam traveled a projected 433 feet, his third-longest homer of the Statcast™ era, with an exit velocity of 106.1 mph, tied for his fourth-hardest since Statcast™'s inception.
Belt's second homer was almost as prodigious. It traveled a projected 410 feet with an exit velocity of 105.2 mph. The launch angles of 26 and 27 degrees, respectively, were virtually identical.
Belt, who said he hadn't hit a grand slam since connecting in a Triple-A game at Memphis in 2011, tried to remain calm when he found the bases full in the sixth.
"You don't want to get too amped up or too anxious while you're up there, so I just wanted to keep it like any other at-bat," he said.
Belt last recorded a multiple-homer game on Aug. 11, 2015 against Houston. He drove in five runs, one short of his career high of six RBIs in 2013.
Chris Haft has covered the Giants since 2005, and for MLB.com since 2007. Follow him on Twitter at @sfgiantsbeat and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.