It’s a bashing by the Bay as Dodgers are blown out by rival Giants

The groundball moved at a torturous pace, like a snail without purpose, a sloth on vacation. Off the bat of San Francisco Giants outfielder Eduardo Nunez, it crashed into the dirt in front of home plate. It hopped over the mound, beyond the reach of Dodgers starting pitcher Brandon McCarthy. It trickled into shallow center field, and, at last, settled into shortstop Corey Seager’s glove.

And that was when, in the fourth inning of an 8-1 Dodgers loss, things really went awry.

The scene disoriented McCarthy. First he saw the shards of Nunez’s shattered bat. Then, after he tried to glove the ball, he was stuck in the middle of the diamond. He was not supposed to be there.

“There were a lot of things going on, I guess,” McCarthy said.

When Seager turned toward the diamond, he threw to McCarthy. One run had already scored. Another runner, Giants shortstop Brandon Crawford, drifted toward the plate. McCarthy set his sights on Nunez, who was trying to go to second. McCarthy spun 360 degrees, ignoring Crawford as he ran home. As Crawford scored, McCarthy threw to second. Nunez was safe too.

It was the lowlight of a four-run inning, one that allowed the Giants to break free and hand starter Matt Cain a lead the Dodgers could not dent.

“The fourth inning got away from him,” manager Dave Roberts said.

In his return from the disabled list, McCarthy (3-1, 4.15 earned-run average) gave up six runs on eight hits in 52/3 innings.

The defense behind him did him few favors. His offense did him almost none, staying quiet until a three-run rally in the ninth.

For the second time this season, Cain held sway over the Dodgers. He limited them to two hits in six innings April 24. On Monday, he gave up five hits but only one run in 62/3 innings. He threw 112 pitches, his most in a game since April 12, 2014.

Two weeks ago, during an exercise with kettle bells, McCarthy suffered a dislocated left shoulder. He considered himself capable of pitching. The Dodgers chose to put him on the 10-day disabled list instead.

He returned Monday for his first appearance since April 29.

Rust was not an issue at the outset. McCarthy retired the first seven batters he faced.

He even showed some dexterity as a hitter, lining out in his first at-bat.

The two clubs traded runs in the third. Seager chipped a two-out single up the middle that bounced off Cain’s glove and into the outfield. Up next, Yasmani Grandal skied an RBI double into right center.

San Francisco scratched together a rally in the bottom of the inning. McCarthy gave up a one-out single to outfielder Mac Williamson. Cain bunted Williamson to second.

On a 2-2 fastball, Giants outfielder Denard Span punched a 94-mph fastball into left for a score-tying single.

In the fourth, the Giants pestered McCarthy more punishingly.

He gave up singles to first baseman Brandon Belt and catcher Buster Posey. Crawford smashed a cutter down the first-base line. The ball bounded past Chase Utley for an RBI double.

Nunez came up next and incited chaos. After he drove in two runs, he stole third base. That put him in position to score on a sacrifice fly by rookie third baseman Christian Arroyo.

The Giants pushed across another run against McCarthy in the sixth. By then, the damage was done.

“Not a lot of loud contact,” McCarthy said. “Just quality aiming.”

Short hops

Adrian Gonzalez (elbow soreness) and Logan Forsythe (broken toe) are expected to begin rehabilitation assignments Tuesday with Class-A Rancho Cucamonga. Gonzalez is slated to play seven innings at first base. Forsythe will be the designated hitter. Gonzalez will need at least two games before he rejoins the big league club, Roberts said. Forsythe will need more time, though Roberts did not reveal specifics.

andy.mccullough@latimes.com

Twitter: @McCulloughTimes