SAN DIEGO -- The Pacific Stock Exchange once called San Francisco home.

The Giants’ Pacific Sock Exchange planted its flag in San Diego as they flexed their brawn in a 7-6 victory over the Padres on Sunday afternoon at Petco Park.

Matt Chapman belted a two-run home run before Jerar Encarnacion and Luis Matos stroked back-to-back homers as the Giants scored six runs in the fourth inning and held one to snap a four-series losing streak.

And that wasn’t the highlight of the day for Chapman.

“I’m trying to catch a flight,’’ Chapman said postgame. “We might be having a baby.”

What a tale Chapman can someday tell his child about a six-run, three-homer inning, when the Padres’ Joe Musgrove went from unhittable to unwatchable.

The fabulous fourth started innocently enough for the Giants after Musgrove had set down the first 10 batters he faced, with six of them being strikeout victims.

Heliot Ramos sent a harmless fly ball to right fielder Fernando Tatis Jr. But Tatis, for some reason, wasn’t wearing sunglasses on a sweltering afternoon when the first-pitch temperature was 91. Tatis lost the ball in the sun. By the time he gathered it, Ramos was on second with a solar double.

That was just the first black cloud for Musgrove as he unraveled and allowed seven straight hits.

Chapman smoked a center-cut fastball for a two-run homer, followed by a rope of a single by Michael Conforto. Another single by Tyler Fitzgerald set the stage for Encarnacion’s three-run drive that landed high up in the right-field seats. Matos joined the party with a solo shot, and Marco Luciano ended the hit parade with a double.

Order was restored when the Saturday night star, Grant McCray, struck out for the second time in the frame, but not before the Giants had left their mark.

Right-hander Spencer Bivens was the recipient of the Giants’ visit to muscle beach, in his second career start. He allowed a run, four hits and a walk over 4 1/3 innings, with three strikeouts. Most of Bivens’ appearances have been as a reliever.

“I was always a starter in college, so I strive to do that,’’ Bivens said. “But whatever they ask of me, I do my best and I am thankful that they trust me. I’m just doing what I can to help the team win.”

San Francisco’s bullpen did the rest of the heavy lifting, although there were some nervous moments along the way.

Luciano, Fitzgerald exchange words after collision
When the Padres' Jurickson Profar popped up to Luciano near second base in the seventh inning, it didn't seem like a big deal. But the lack of communication between Luciano and the shortstop Fitzgerald led to the ball dropping for a two-run error on Fitzgerald.

Between innings, Luciano and Fitzgerald exchanged words in the dugout, which motivated third-base coach Matt Williams to step between them.

"The way I see it, probably Fitzy went too far because Luciano probably didn’t call it,” Giants manager Bob Melvin said. “So in a ballpark like this, when you can't hear something, there was maybe some indecision. Fitzy being the quarterback, as the shortstop, probably went a little too far.''

Same goes for the dugout dustup.

"The guys were talking about it a little bit more than they should have,'' Melvin said. "And that's not acceptable either. I'll handle it."

Both players are learning new positions.

"We just don't have that connection in the middle, where we are communicating on the same page,'' Fitzgerald said. "I'm not blaming it on him, but I’m trying to get him to be louder. If I don't hear anything, I'm going to run over there and make a play."

Added Luciano, through an interpreter: "I think it is just miscommunication on both of our parts. I called it, but he didn’t hear me because it was so loud in the stadium. I didn't hear him calling for it.”