SAN FRANCISCO — The Giants finished off a brutal sweep with what may have been their sloppiest performance of the year.
Three errors and five double-play grounders added up to a 4-0 loss to the Diamondbacks and Rubby De La Rosa, who brought a 5.84 ERA into the day but took a shutout bid into the ninth.
The Giants have lost eight straight at home for the first time since 1993.
Two Brandon Crawford errors on one play put the Giants in a hole in the second inning, and Chris Heston dug deeper in the fifth. He had loaded the bases in the fourth and gotten out of the jam, but the Diamondbacks made the rookie pay when he loaded up again in the fifth.
Ender Inciarte led off with a single and Paul Goldschmidt walked with one out. After David Peralta’s single to left, Chris Owings smoked one off the base of the wall in center, giving the Diamondbacks a 3-0 lead.
Another run was tacked on in the sixth when Justin Maxwell dropped Inciarte’s fly ball to center. The Giants didn’t pay much attention to Inciarte and he stole third, then scored on a sacrifice fly.
In the meantime, the lineup was finding no traction against De La Rosa, who gave up 16 runs in his previous two starts. The Giants hit into double plays in the first, third, fifth and seventh innings. They had not hit into four double plays since Aug. 25, 2014.
The bases were loaded ahead of Maxwell with one out in the ninth and Bruce Bochy called on Buster Posey. He hit into a double play.
Starting pitching report: Jake Lamb got the first hit off Heston in 12 days when he flared a double down the right-field line in the second. In all, Heston allowed seven hits and three runs — two of them earned — in five innings. He walked four and struck out six.
Bullpen report: Javier Lopez had his first two-inning appearance since July 17, 2011. He walked one and struck out two.
At the plate: Making his first start since returning from Triple-A, Casey McGehee hit into an inning-ending double play with the bases loaded in the first. He came up with a runner on first in the fourth inning and hit into another double play, the crowd booing before the ball was even thrown to second. McGehee spent two weeks in the minors and hasn’t really played since returning, but he leads the National League with 14 GIDPs.
In the field: It was an up-and-down day for Crawford. He bobbled Welington Castillo’s grounder in the second and then compounded that mistake by skipping the throw to first, allowing a run to score. But an inning later Crawford made a heads-up play to sniff out a rally. Inciarte was on second when Goldschmidt hit a slow roller to short. Crawford faked a throw to first and then turned and easily threw out Inciarte, who never broke stride as he rounded third and headed for home.
Attendance: The Giants announced a crowd of 41,310 human beings. Steph Curry did not attend, for obvious reasons.
Up next: A split four-game series against the Seattle Mariners. The Tims take on Taijuan Walker (3-6, 5.40) and J.A. Happ (3-2, 3.72) at AT&T Park and then the teams head up the coast for two more in Seattle. Ryan Vogelsong and Mike Montgomery square off Thursday, but the real gem is Wednesday, when Madison Bumgarner faces King Felix (9-3, 3.38).