NEW YORK -- The Giants have mostly been successful at running bullpen games this year, but the unconventional pitching strategy went awry in an 8-4 loss to the Mets on Sunday night at Citi Field.

Left-hander Alex Wood gave up five runs (four earned) over 1 2/3 innings in relief of opener Ross Stripling, and the Giants couldn’t fully capitalize on several late-inning scoring opportunities, culminating in a loss that sealed a 2-4 road trip to Toronto and New York.

Stripling cruised through two scoreless innings on 24 pitches, but manager Gabe Kapler decided to bring in Wood to face the left-handed-hitting Brett Baty to start the bottom of the third. It seemed like an ideal landing spot for Wood, but the 32-year-old veteran struggled to grip the ball in the humid conditions, which hampered his ability to land his offspeed pitches for strikes.

An erratic Wood ended up issuing four walks, hitting a batter and needing 57 pitches to record just five outs. Pete Alonso’s bases-loaded walk kicked off a three-run third, and the Mets added two more in the fourth on a solo shot by Mark Canha and a two-out RBI double by Tommy Pham that was misplayed by rookie outfielder Luis Matos.

“I just had a hard time getting a grip,” Wood said. “I was in the ‘pen and I had rosin on my hand. It actually got pretty sticky with the humidity, stickier than it normally is, so I started taking a little bit off my hand. I went out there and started pouring sweat and I just couldn’t strike my offspeed. I had a hard time getting a grip. That was the main culprit.”

“It felt like it was the right spot for Woody,” Kapler said. “It didn’t work out.”

The Giants trailed, 5-1, entering the seventh inning, but they pulled within one by scoring three runs off Mets reliever Jeff Brigham. After Joc Pederson drew a leadoff walk, rookie Blake Sabol breathed new life into the club by driving a 2-2 fastball the other way for his first career pinch-hit home run. Thairo Estrada then singled and scored on J.D. Davis’ RBI double to make it 5-4, but the Mets got a run back on Starling Marte’s RBI single in the bottom of the seventh.

San Francisco came back to load the bases with two outs in the eighth, but Adam Ottavino struck out Davis swinging on three consecutive fastballs to end the inning. Rookie Ryan Walker later surrendered a two-run blast to Pete Alonso that put the game out of reach for the Giants, who finished 0-for-8 with runners in scoring position en route to dropping consecutive series on the road for the first time since April.

While he hadn’t started a game since May 17, Stripling remained stretched out while working his way back from a back injury and could have provided the Giants more length. Still, Kapler said he felt confident that Wood would be capable of getting through a significant portion of the game after firing five shutout innings in his last bulk-relief appearance against the Blue Jays on Tuesday.

“I liked the idea that Alex could start a fresh inning there with a left-right-left and get his outing going,” Stripling said. “I get that it maybe makes sense to have me roll through it again with a shorter pitch count, but that kind of went to script, the script that we had and we were comfortable with going into the game. It just didn’t work out, obviously, but it was what we scripted and a good set-up, and felt like the right call at the time. Always easier to say in hindsight, I guess, but in real time it felt like what we had discussed.”

The Giants will have to turn the page quickly, as they were scheduled to fly back home following Sunday night’s game and land back in San Francisco around 3 or 4 a.m. PT on Monday. They have a night game against the Mariners at Oracle Park on Monday, followed by a day game on the Fourth of July, further compounding the challenging travel schedule.

The Giants are hoping they’ll get a boost from the return of outfielder Mike Yastrzemski, who will likely come off the injured list on Monday, but they also left New York with fresh concerns. Estrada took a 91.7 mph sinker off his left hand, and Brandon Crawford appeared to hold his side after making a diving play on Marte’s grounder to end the eighth. Both are expected to be re-evaluated prior to Monday’s series opener.

“We’re going to put one foot in front of the other and be ready,” Sabol said. “We were in that game. I think we still gave it our best shot. I think when we get back home, we’ll get a couple of guys back and hit full stride again.”