"It's nice to know that up and down the lineup right now we have some guys that can do some damage," Giants manager Gabe Kapler said. "It's encouraging what we've seen our guys do over the course of the last two or three weeks."
Solano, who got off to a scorching start at the plate this season, came in hitting just .216 over his past 12 games. But he went 3-for-3 Sunday with a double and single to go along with his third homer.
He hit a first-pitch sinker from Alex Young (1-3) in the sixth for a two-run shot to left that erased a 2-1 San Francisco deficit.
Belt came off the bench to deliver a pinch-hit solo shot in the seventh to extend San Francisco's lead to 4-2 and continue his torrid streak at the plate.
He's hitting .491 (27 for 55) over his past 19 games.
"He's been amazing, like nothing I've ever seen," Giants outfielder Alex Dickerson said. "He's always a guy you fear, always a guy you fear to either walk or hit a ball hard, and he's just doing it at an unbelievable rate right now."
Tromp, drawing the start behind the plate, homered in the third to cut the Giants' deficit to 2-1.
San Francisico starter Johnny Cueto steadied himself after a shaky first inning and held the Diamondbacks to two runs over 5 2/3 innings. Both runs came in the first, including Tim Locastro's homer to lead off the game.
Arizona advanced a runner as far as third base in just two other innings after the first.
Cueto escaped the fifth unscored upon after putting runners on the corners with no outs. He got a lift from first baseman Wilmer Flores, who fielded a safety squeeze bunt attempt from Locastro and nailed Nick Ahmed at the plate.
"We had a chance to really blow that game open, there's no doubt about it," Diamondbacks manager Torey Lovullo said.
Dickerson and Darin Ruf each turned in excellent catches in left field that they had to leave their feet for.
Asked about them after the game, Kapler replied: "It's interesting you bring those two guys up. They are viewed as offensive-first, but nobody on our team takes their defense more seriously than those two guys."
Arizona recalled INF Wyatt Mathisen from its alternate training site and optioned RHP Artie Lewicki. It's the first major league call-up for Mathisen, 26. . San Francisco recalled RHP Rico Garcia from its alternate training site and optioned LHP Andrew Suarez.
Diamondbacks: LHP Caleb Smith, scratched from an outing Saturday at Arizona's alternate training site because of mid-body soreness, threw in a game Sunday instead.
Giants: LHP Drew Smyly (sprained left index finger) and RHP Jeff Samardzija (inflammation in pitching shoulder) both came out of Saturday's simulated games feeling OK. Manager Gabe Kapler said Samardzija could be brought back as a starter or a long reliever.
Zac Gallen (1-0, 1.80 ERA) starts Monday's series finale and will look to extend his Major League record streak of 23 games to start a career with three or fewer earned runs allowed (all starts). The Giants' Kevin Gausman (2-2, 4.43 ERA) has won two of his past three starts.
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