Widely considered an above-average defender, Belt couldn't grab Jake Lamb's fifth-inning grounder that scooted through him and down the right-field line with two outs and a pair of D-backs on base. The runners scored, and so did Lamb before the inning ended. The uprising erased San Francisco's 4-1 lead and launched Arizona's seven-run surge from the fifth inning through the seventh.
Belt, who called the play "routine," tried to backhand the ball, which took a mildly tricky hop.
"It wasn't a terrible hop," said Belt, who tripled and homered before his unfortunate encounter with Lamb's grounder. "But I was just kind of in between. If you can on those plays, you want to try to get your body in front of [the ball] so that if it does bounce up, you can knock it down.
"... It changed the momentum, changed the whole game for us."
Giants manager Bruce Bochy shared that perception.
"Belt catches that ball 95, if not 99 percent of the time," he said. "That was a momentum changer there."
Arizona manager Torey Lovullo defended Belt: "[Lamb] hits a ball down the right-field line. For me, it should have been a hit."
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.