NEW YORK -- The rain came lightly at first, then heavier -- heavy enough for umpires to consider putting a halt to Thursday’s game between the Mets and Cardinals before the ninth inning began. Near the third-base dugout, grounds crew members gathered, prepared to roll out the tarp if needed.

Eventually, they did, just as the rain began to lighten. So they rolled it back up again while other workers applied Diamond Dry to the infield. It wasn’t a perfect solution, but it was enough to play host for the Mets nightmare that followed: closer Edwin Díaz allowed two runs in the ninth, before the rain came again -- this time heavy enough to result in a suspended game. The teams will resume the game Friday at Citi Field with the score tied, 4-4, in the bottom of the ninth.

• Gameday

“Overall conditions for both teams were tough right there with the rain, how wet it was,” Mets manager Mickey Callaway said. “Guys [were] slipping and bobbling. But we both had to play through it. And the good thing is the game’s not over yet.”

The game appeared nearly over when Diaz began warming in the eighth. Jacob deGrom offered the Mets seven standout innings, Michael Conforto hit a two-run homer and Dominic Smith gave them the lead with an RBI single.

After deGrom exited, Seth Lugo struck out the side in the eighth to edge the Mets within three outs of a victory that would boost them back to .500 for the first time since May 26.

By that point, the front edge of a storm had rolled into Citi Field. As Diaz prepared to make his warmup pitches for the top of the ninth, grounds-crew members jogged out to the field hauling bags of Diamond Dry, hoping to make the infield playable enough for three more outs.

The rain kept coming, though, forcing umpires to call for the tarp -- until the rain stopped, that is, and the tarp went back again.

“If you can get the game in and you're playing in the conditions that are suitable to play in, I think you try to do that,” crew chief Jeff Kellogg said. “But once it became where it’s not, then I think you’ve got to say, ‘OK, let’s stop.’ It wasn't an easy one.”

“They did all they could,” Callaway said. “They’re trying to get a game in. That’s their responsibility. I think they did everything they could.”

Conditions were not ideal for Diaz, who endured a lengthy delay before taking the mound, then walked the leadoff batter on five pitches. Diaz recorded two outs from there, but Kolten Wong followed with an RBI single and Harrison Bader hit a game-tying double. The Mets might have had a play at the plate, but Amed Rosario dropped Carlos Gomez’s relay throw, allowing Wong to score without much drama. Bader then stumbled on his way to third, allowing Diaz to escape the inning.

Rain grew heavier from there, prompting the grounds crew to bring the tarp out one more time and, ultimately, for umpires to suspend the game shortly before 11 p.m. ET. The teams will resume play at 6:10 p.m. on Friday, prior to the start of the regularly scheduled 7:10 p.m. game. Fans with tickets to Thursday’s suspended game can exchange them for another regular-season home game on a Monday through Thursday (excluding the Subway Series).

When play resumes, Callaway said, Diaz is likely to return to the mound.

“This game’s not over with,” the manager said. “We’re going to come back out here [Friday] and get a win.”