Julio Urias’ gem undone by Brandon Belt homer in Dodgers’ 2-1 loss

The education of Julio Urias entered its fourth stage on Sunday night, with the 19-year-old pitcher venturing deeper into a major league game than ever before. His first three outings reinforced the necessities of relentless concentration and expedient efficiency, and for five innings against the San Francisco Giants, Urias demonstrated his facility with both tasks.

But in the sixth inning of a 2-1 defeat, he received a reminder, one he learned against the New York Mets at Citi Field and the Chicago Cubs at Wrigley Field. At this level, mistakes do not go unpunished. On his 86th pitch, Urias threw a slider to first baseman Brandon Belt. The pitch hovered over the plate. Belt drove it out of sight.

The two-run homer blemished his line and taught Urias another lesson about being a pitcher for the Dodgers in 2016: The margin for error is so slim. His offense provided scant support, and the club continued a stretch of offensive malaise that has frustrated the players, coaches and front office.

“I don’t have an answer,” Manager Dave Roberts said. “I know that it’s not from lack of preparation, or as far as talent within the group. I don’t have an answer.”

Save for a home run by Joc Pederson in the seventh inning, Urias (0-2, 5.82 earned-run average) was the Dodgers’ lone bright spot. He struck out seven and held the Giants to four hits. He pumped fastballs past his opponents and fooled them with changeups and sliders. After a trio of fitful outings, Urias appeared on the verge of a small masterpiece.

Belt altered that narrative with one swing. He also heightened the misery for the Dodgers, who dropped two of three in San Francisco in frightful fashion. After capturing a victory on a ninth-inning homer on Friday, Kenley Jansen kicked away Saturday’s game and the lineup declined to contribute in Sunday’s series finale.

The Dodgers exit the Bay Area trailing the Giants by five games in the National League West. The deficit is manageable, especially at this early juncture, but the team’s inability to sustain momentum has prevented it from leap-frogging a wounded San Francisco team.

Discontent burbled to the surface midway through the eighth inning, after Justin Turner argued with umpire Mike Muchlinski over a called third strike. Muchlinski ejected Turner. Roberts guided Turner back into the dugout as his third baseman hollered at crew chief John Hirschbeck.

“It just feels there’s certain place where you go [that] umpires are always going to be one-sided,” first baseman Adrian Gonzalez said. “This is one of them, Yankee Stadium. There’s certain places where the crowd plays a factor. But we’ve dealt with that, and we know we can win despite that. That’s definitely not the reason we lost today.”

Urias made his second start paired with veteran catcher A.J. Ellis. The duo navigated through the first five innings without much trouble. Urias set the tone for his outing when he pumped a 95-mph fastball past Belt to end the first. Urias showed an impressive “ability to finish guys with his fastball today,” Ellis said.

Yet the Dodgers offense provided so little. Jake Peavy took the mound with a 6.41 ERA. He had given up four runs or more in seven of his 12 outings. On Sunday, he spun six scoreless innings. He allowed only one Dodger to reach third base.

“He doesn’t have the stuff that he used to have,” Roberts said. “You expect to put some runs on the board.”

Chase Utley collected three singles against Peavy. The rest of the lineup went one for 18 with one walk. Howie Kendrick took the walk in the fifth, right after Pederson hit a leadoff single. The offense appeared to be rousing itself from a slumber.

Up came Ellis. Peavy flipped a 1-and-1 curveball down the middle. Ellis rolled a grounder toward second base. The Giants turned a double play, and Urias flew out to end the threat.

“It’s not about [the offense letting down] Julio, it’s about the Dodgers, it’s about us not winning,” Ellis said. “The offense failing to come through once again, myself included.”

In the sixth, Urias gave up a one-out single to second baseman Joe Panik. His slider to Belt “wasn’t a terrible pitch, it just got a little too much of the plate,” Roberts said. Urias exited after 51/3 innings.

Pederson halved the deficit in the seventh inning. But the Dodgers produced only one baserunner after his home run against reliever Hunter Strickland. Turner sparred with the umpires. Gonzalez attempted an unsuccessful bunt against lefty specialist Javier Lopez in the ninth.

And a troubling pattern only continued for the Dodgers, a broken record skipping since April.

“For us, it’s just a matter of staying the course,” Roberts said. “And just continuing to try to improve and get results. Because at some point, you’ve got to score runs.”

Andy.mccullough@latimes.com

Twitter: @McCulloughTimes