Trying to become the first major league pitcher to win four road games in one postseason, deGrom ran into a Kansas City lineup that caused him fits with consistent contact.
Only three times did the Royals swing and miss against the right-hander, a career worst for deGrom, according to STATS. He managed only two strikeouts, matching a season low.
"I wasn't really surprised by it. Kind of knew that going in. Early on, pitch count was staying pretty low because I knew they were going to be attacking," deGrom said.
Like fellow ace Matt Harvey the night before, deGrom faded in the middle innings and squandered a lead.
Now, after throwing two of their top starters in Kansas City, the reeling Mets will turn to rookie Noah Syndergaard in Game 3 on Friday night, hoping he has more left in the tank than the teammates who preceded him.
"We win because we ride our starting pitching. When they struggle we're going to struggle, and that's what's happened," manager Terry Collins said.
After all New York did this year to rest and protect its prized young arms, they might be running out of fuel in late October anyway.
"That certainly is a possibility. I'm not going to say it's not," Collins said. "But I'm not going to sit here and say that. It's the World Series. We've got to make pitches and we're not making them.
"It's easy to make excuses that, hey, it's the workload, it's the days off, it's the youth, on the big stage. I'm not going to say that," he added. "Look, the Royals have a good team. We've got to make better pitches and we've got to play better."
Last season's NL Rookie of the Year, deGrom has tossed 216 innings in 2015, including the postseason.
Still, pitching coach Dan Warthen doesn't see fatigue.
"He just got the ball up. Left some pitches in the zone, made some mistakes," Warthen said. "Got a little amped up and that's what happens with him, and his arm will get underneath and everything will flatten out."
Collins thought a five-day break between the NLCS and World Series would help his young pitchers, but it hasn't looked that way. After going 3-0 with a 1.80 ERA and 27 strikeouts in three playoff starts, deGrom couldn't keep it going against the AL champs.
He came out firing 97-98 mph fastballs and zipped through three hitless innings on 38 pitches. But first baseman Lucas Duda booted a leadoff grounder in the fourth for an error, and deGrom worked hard to get out of trouble.
He retired Salvador Perez on a bases-loaded grounder to end the inning, but lost his touch in the fifth. The shaggy-haired deGrom issued a leadoff walk to Alex Gordon on a full-count slider and yielded an RBI single to Alcides Escobar on an 0-2 pitch.
"They did exactly what people said, and they put the ball in play," Collins said. "I told Jake not everything has to be a strike. You've got to move it around. You've got to change speeds, give them something to look at. If you continue to pound the strike zone, they're going to put it in play, and that's what they did."
Two outs later, Eric Hosmer snapped a 1-all tie with a two-run single and Mike Moustakas made it 4-1 with an RBI single. Kansas City batted around and had five singles in the inning.
"I just wasn't able to make the pitch when I needed to there," deGrom said.
Collins stuck with deGrom the entire inning, hoping he could wriggle out of a mess yet again.
"This guy has been our ace. You have to stay with him. We've been sitting here raving the last two series that he's gotten himself out of trouble," Collins said. "It was just one of those nights. Jake has gotten out of those situations a lot of times."
The tenacious Royals fouled off 23 pitches against deGrom, 14 in the fifth, and it took him 35 pitches to get through the inning.
He was lifted for Hansel Robles to start the sixth.
"I've learned that they hit mistakes very well. I've learned that they don't try to do too much with the baseball. They keep the line moving," catcher Travis d'Arnaud said.
It was the first time since Sept. 22 that a Mets starter gave up four runs — and that was fill-in Logan Verrett, who isn't even on the postseason roster.
Meanwhile, the Mets managed only two soft hits by Duda off Johnny Cueto in his complete game.
"By no means are we done," Duda said. "We've created a hole for ourselves, but we've been here before."