PHILADELPHIA -- Clayton Kershaw has three Cy Young awards, four ERA titles and seven All-Star appearances on his résumé at age 29, so it stands to reason that he should be the answer to a trivia question or two.

When Philadelphia Phillies outfielder Aaron Altherr stepped to the plate in the sixth inning with the bases loaded Monday night, history suggested that Kershaw had things under control. In his career, he had faced 103 batters with the bases loaded and had never allowed a grand slam. Among active pitchers, only Matt Cain (133) and Zach Duke (114) have faced more hitters with the bases juiced and gone slam-free.

All it took was one bad pitch to knock Kershaw out of the company of Jim Palmer in the no-career-slam club and sour his mood for the evening. One hanging slider. One exasperated ace. And the Los Angeles Dodgers continued to sputter their way toward a National League West clinching party.

In his fourth start since his return from a lower back injury, Kershaw was fine during his first two spins through the order. He was sitting on a 2-0 lead to start the sixth. But an uncharacteristic bout of wildness preceded a big mistake, and the Dodgers lost 4-3 to kick off a four-game series at Citizens Bank Park.

Kershaw is as competitive as it gets, and he didn’t make much effort to conceal his displeasure during a postgame group interview session that lasted all of three minutes. He had reason to lament the two walks he issued to Ty Kelly and Rhys Hoskins every bit as much as the long ball he surrendered to Altherr.

“No progress,” Kershaw said when asked for potential bright spots. “We had the lead, and I blew it, and we lost, so there’s not a lot of progress there to be had. Just go back to the drawing board and figure it out for the next one.

“It wasn’t great all night. I had trouble putting guys away with two strikes. A lot of extra pitches. I was fortunate to get out of a few of them. But it caught up to me, I guess.”

Kershaw is 17-4 with a 2.26 ERA, a 0.93 WHIP and 194 strikeouts in 163 innings this season, so the term “struggling” is all relative. But his average velocity of 92.8 mph is down a tick from the past couple of seasons, and he has joined the burgeoning fraternity of pitchers whose home run totals have spiked this summer. Kershaw has already allowed a career-high 21 homers despite missing five weeks with a lower back strain.

Since his return from the disabled list on Sept. 1, Kershaw was sharp against San Diego, shaky against Colorado and so-so against San Francisco before taking on the Phillies, who usually go down meekly against him. According to the Elias Sports Bureau, Altherr’s home run broke Kershaw’s 32-inning scoreless streak against Philadelphia -- his longest versus any team in his career. It was the longest scoreless streak by any pitcher against the Phillies since the Mets’ Tom Seaver blanked them for 38 consecutive innings from 1969-70.

“It was a surprise to all of us, because when there is traffic or stress, Clayton always finds a way to make that pitch to get the strikeout or the ground ball,” Dodgers manager Dave Roberts said. “Right there, I liked our chances. It was just two walks and a mistake breaking ball.”

The Dodgers appeared to have regained their equilibrium after losing 16 of 17 during a colossal late-season slide. They beat the Giants twice in San Francisco, then rolled into Washington and took two of three from the Nationals to reduce their magic number in the NL West to four. But questions continue to linger around the team. Catcher Yasmani Grandal and outfielder Curtis Granderson are in the middle of prolonged slumps, shortstop Corey Seager is fighting an achy elbow, and the Dodgers’ setup relievers have been merely OK (with the exception of Brandon Morrow).

A dominant effort by Kershaw would have continued the momentum into this week, but now he has re-entered the work-in-progress phase of his comeback.

“He’s not quite there yet,” Roberts said. “You can see him feeling for things. But there are signs as we look forward to the postseason that he’s going to be where he needs to be. We talked about him needing four to six starts to get ready. And he’s at four, so I definitely know he’s trending in the right way. Tonight, it’s one pitch. If he gets the out, we’re talking about what a stellar outing it was.”

But he didn’t. And they weren’t. The Dodgers have ridden Clayton Kershaw awfully hard over the years. Now they’re going to have to exercise a little patience so he can get himself right for the games that matter most.