SAN FRANCISCO -- Ideally, the Arizona Diamondbacks would have seized upon this four-game series against the struggling San Francisco Giants to escape the treadmill of remaining at or around the .500 mark.

But the D-backs, who outscored San Francisco 34-8 during a three-game sweep May 24-26 in their last visit to Oracle Park, lacked that dominance this time. They were forced to content themselves with a split of this series, which concluded Sunday with San Francisco’s 10-4 victory.

The outcome left Arizona with -- you guessed it -- a .500 record (43-43). It marked the seventh time in June that the D-backs occupied this neutral corner.

• Box score

Nothing’s wrong with being a .500 club. Except that it inevitably expects to be better, no matter which sport it’s playing or league it inhabits. And, obviously, as the schedule elapses, the opportunities to escape the doldrums of .500 dwindle.

Put it this way: The D-backs remain only two games behind the pacesetters in the race for the National League’s second Wild Card berth. The standings are unlikely to look that promising if Arizona stands at .500 come September.

That’s why this week is a critical one for the D-backs. They’ll visit NL West-leading Los Angeles for two games before entertaining Colorado for three games that lead into the All-Star break. Arizona’s 16-27 record against West opponents does not inspire confidence entering this stretch.

“It’s a little bit frustrating within our division,” D-backs manager Torey Lovullo said, “because I know we’re a better team than we’ve shown. ... I know [the intradivision record] is not up to my standards.”

Facing the division’s top two teams at this juncture does not set up a win-or-else scenario for the D-backs. But they missed a chance to pull away from .500 with a better series against San Francisco. Granted, duplicating their previous trip here would have been a little much to ask of the D-backs, even against a last-place outfit such as the Giants. Still, having captured two of three games against the Dodgers before arriving here, the D-backs surely had higher expectations than leaving here at .500. Now, Arizona must strive to remain relevant by subduing more difficult competition, denying the D-backs the luxury of cruising into the All-Star break.

“We have to get on a roll,” D-backs right fielder Adam Jones said. “We have to get on a two-week stretch where we play .700 ball.”

The D-backs had plenty of reason for optimism on Sunday. Left-hander Robbie Ray, their starter, owned a 5-1 record with a 3.01 ERA in 13 career starts against the Giants, whose lineup included seven position players batting .243 or lower.

But the Giants jumped on Ray quickly, scoring pairs of runs in the second and third innings. Kevin Pillar thrived for San Francisco, lashing a two-run homer in the second inning and a two-run single in the third.

Ray (5-6) recorded his worst pitching line of the month: four runs and six hits allowed in four innings to go with three walks. Two of those baserunners who walked ultimately scored.

“This was a bit of a head-scratcher,” Ray said. “I felt like I made some pretty good pitches, and they hit them.”

The Giants’ six-run seventh, matching their most prolific inning of the season, settled matters.That was more than enough support to back Madison Bumgarner (5-7), who yielded four hits and Colorado’s lone run in seven innings.

One of the strikes Bumgarner threw in the fifth inning angered Lovullo enough to prompt him to argue with plate umpire Mike Muchlinski, resulting in an automatic ejection.

“He asked me if I had anything I wanted to say, and I did,” Lovullo said. “I’m not proud of it, but I have to battle for our guys in the right place at the right time.”