OAKLAND, Calif. – The A’s won’t be mistaken for a major league operation anytime soon, so the Mets really have no excuse if they fail to sweep this weekend series.

For much of Saturday afternoon manager Buck Showalter’s crew looked somewhat lethargic, but finally a late-inning surge arrived that got the Mets two-thirds of the way toward that goal.

One part power, one part grinding at-bats, the Mets rallied for a 3-2 victory that gave them a three-game winning streak for the first time this season.

This one wasn’t nearly as easy as the previous night’s laugher in which the Mets set a franchise record by drawing 17 walks.

The Mets scraped for the necessary runs and Adam Ottavino walked a tightrope in the eighth, escaping after walking two batters, before David Robertson got the save, leaving the tying run at third base in the ninth.

Mark Canha’s homer leading off the seventh awoke the Mets, who had just three hits to that point.

The blast to left field that tied it 2-2 provided a nice homecoming for Canha, who came to the Mets before last season after spending seven years with Oakland.

But the Mets weren’t finished in the inning.

After Daniel Vogelbach walked to end Shintaro Fujinami’s afternoon, pinch-runner Tim Locastro stole second and scored on Brandon Nimmo’s double against Trevor May, giving the Mets a 3-2 lead.

In a rebound performance, Carlos Carrasco pitched five-plus innings and allowed two earned runs on four hits with a walk and two hit batters.

It marked the first time in three starts this season the right-hander completed five innings.

Carrasco in his previous two starts had surrendered five and six runs, respectively, against the Brewers and Marlins.

Carrasco fell into a 2-0 hole in the second after Aledyms Diaz’s double put runners on second and third with nobody out.

Conner Capel’s RBI ground out put the A’s ahead before Carlos Perez was hit by a pitch with two outs and Esteury Ruiz delivered a single for the second run.

In the fourth, Carrasco plunked Ruiz to load the bases with two outs, but escaped by retiring Tony Kemp.

The threat started with Jesus Aguilar’s double and a walk to Perez with two outs.

Pete Alonso’s homer in the fourth pulled the Mets within 2-1.

The blast was the seventh this season for Alonso, who has sizzled in his limited appearances in this ballpark: In five games here he’s homered three times and driven in eight runs.

Starling Marte was drilled by a pitch to begin the sixth and stole second.

The ensuing batter, Francisco Lindor, tried to walk on ball three, but was called back to the box after a consultation by umpires.

Lindor’s ground out moved Marte to third, but he was left stranded as Fujinami retired Alonso and Jeff McNeil in succession.