Through the first four innings of Sunday's contest, Arizona Diamondbacks left-hander Vidal Nuño's homecoming was going rather swimmingly.
Nuño, a native of California, was making his second career start in his home state -- an experience that turned quickly with one swing of the bat at AT&T Park.
The D-backs' recent addition to the rotation survived the first four frames with relative ease but that pattern wouldn't hold.
Staked to a 1-0 lead, Nuño promptly gave it back in the fifth. After striking out Brandon Crawford to begin the inning, the 26-year-old allowed a double to opposing pitcher Madison Bumgarner, hit Hunter Pence with a pitch and surrendered an infield hit to the fleet-of-foot Pablo Sandoval.
With the bases full of Giants, former MVP Buster Posey took matters into his own hands, smashing a 1-0 fastball into the left field bleachers for a game-altering grand slam.
Bumgarner continued the offensive theme in the sixth inning, smacking his second career grand slam off of Matt Stites to pad the Giants' lead.
Supported by Bumgarner and Posey's blasts, San Francisco won the finale of the three-game series going away, 8-4.
Bumgarner and Posey became the first battery mates ever to hit a grand slam in the same game.
3 and 4:
Bumgarner and Posey's grand slams were just the third and fourth home runs D-backs pitching has allowed in its last 15 games.
Before serving up Bumgarner's slam, rookie reliever Matt Stites had only allowed four total runs in 10.1 innings of work.
9 Part I:
Cody Ross, who played with the Giants for parts of the 2010 and 2011 seasons, hit his second home run of the season in the seventh.
The long ball was, however, just his ninth career in San Francisco.
9 Part II:
Martin Prado collected three hits for the ninth time in 2013. Prado's second hit, a single in the third, marked Arizona's first running-scoring play of the afternoon.
With his three-hit performance, Prado heads into the All-Star break rather hot at the plate. In fact, he's hit safely in 11 of his last 12 games.
Dating back to his time with the New York Yankees, Nuño had allowed just one run in 21.2 innings of work before his four-run implosion in the bottom half of Sunday's fifth frame.
Paul Goldschmidt's career-high 32-game streak of reaching base came to an end in the drubbing. Goldschmidt went 0-for-4 but was robbed of extra bases in the sixth on a terrific catch by Pence.
Bumgarner joined Tony Cloninger (1966) Sunday as the only two pitchers to club multiple grand slams in the same season.
Bumgarner's 12 RBI this year are also the most by a Giants pitcher since Juan Marichal's 12 back in 1966.
The Giants' pair of grand slams were not a franchise first. The organization has pulled off the feat three times now, most recently on Sept. 18. 1998 against the Los Angeles Dodgers.