Three runs were nowhere near enough for the Arizona Diamondbacks to win Friday’s series opener against the New York Mets.

Arizona should have scored a lot more than three runs Saturday, but a timely rally nonetheless provided a much-needed feel-good victory.

The Diamondbacks will look to earn a key early season series win Sunday when they conclude a three-game set against the host New York Mets.

Right-hander Humberto Castellanos (0-0, 6.00 ERA) is slated to take the mound for the Diamondbacks against left-hander David Peterson (0-0, 0.00 ERA). Both pitchers are making their first starts of the season.

A three-run seventh inning sparked the Diamondbacks to a 3-2 win Saturday. Sergio Alcantara belted a two-run homer to break a scoreless tie before Ketel Marte added an RBI double three batters later.

“The players, I couldn’t be more proud of them after (Friday’s) game — we just didn’t play our type of baseball to come out and give the focused effort that we (needed) to win the game,” manager Torey Lovullo said of the Diamondbacks, who dropped a 10-3 decision in Friday’s series opener.

Saturday’s win offered some relief to the Diamondbacks, who have scored three runs or fewer in each of their last four games and six times in eight games overall this season.

Even in victory, the Diamondbacks didn’t play their most efficient game. Arizona stranded 10 baserunners and left the bases loaded twice Saturday — including in the top of the ninth, just a half-inning after the Mets pulled within 3-2 on Starling Marte’s two-run homer.

“A couple things we’ve got to tighten up,” Lovullo said. “But a win is a win and we’ll take it.”

The defeat did little to diminish the Mets’ enthusiasm over the early performance of their Jacob deGrom-less rotation. New York’s starters have a 1.17 ERA (six earned runs in 46 innings pitched) after Carlos Carrasco struck out eight over five scoreless innings Saturday.

Tylor Megill, who was ticketed for the minor leagues before replacing deGrom on Opening Day, is 2-0 and hasn’t allowed a run in 10 1/3 innings over two starts. Half of the runs surrendered by Mets starters came in the debut of star free agent acquisition Max Scherzer, who still earned the win with his six-inning stint against the Washington Nationals on April 8.

“It’s really good — it’s going to be like this all year,” Carrasco said. “We’re missing Jake but we got Megill and all these guys. It’s good. We’re going to be fine.”

Peterson will try to continue the momentum when he assumes the rotation spot of Taijuan Walker, who is on the injured list due to right shoulder bursitis. The 26-year-old southpaw made his season debut in place of Walker on Monday, scattering three hits over four scoreless innings in the Mets’ 5-4 loss to the Philadelphia Phillies.

Castellanos, who was inserted into the rotation when the Diamondbacks sent left-hander Caleb Smith to the bullpen, has made two relief appearances this season. He last pitched on April 10, when he gave up two runs in one inning.

Castellanos has never faced the Mets. Peterson is 0-0 with a 36.00 ERA in two starts against the Diamondbacks.

–Field Level Media