NEW YORK (CBSNewYork/AP) — About a half-hour before the first pitch, the Philadelphia Phillies learned the New York Mets had scratched major league ERA leader Jacob deGrom because of a steady rain forecast for all afternoon.

“In a big game, obviously we liked our chances not having to face him,” Rhys Hoskins said.

Hoskins hit a two-run homer in the first inning off rookie Corey Oswalt, but the Phillies could not shake their funk. Vince Velasquez allowed Michael Conforto’s tiebreaking, three-run homer in a four-run fifth inning that propelled New York to a 6-4 win Sunday.

Michael Conforto

Mets outfielder Michael Conforto connects on a three-run home run against the Philadelphia Phillies during the fifth inning at Citi Field on Sept. 9, 2018. (Photo by Rich Schultz/Getty Images)

Since moving a season-high 15 games over .500 with a four-game sweep of Miami that ended Aug. 5, the Phillies have gone 10-20. They are winless in 10 series, losing nine — including seven in a row.

“Of course that’s a missed opportunity,” Hoskins said. “Not because it wasn’t deGrom and we didn’t beat somebody else. Just another series that seemed to slip away.”

Philadelphia led the NL East before play Aug. 12 but started Sunday 3½ games behind first-place Atlanta. The Phillies trailed by the same margin for the second wild card with three weeks left.

After a loss as dismal as Sunday’s weather, manager Gabe Kapler said “we need to turn the page quickly” more often than a speed-reading instructor.

“Things kind of just got out of hand,” Velasquez said. “Missing spots kind of all game. Conditions kind of got the best of me and can’t let that happen.”

Conforto tied a career best with four RBIs and made a fine catch. Rookie Jeff McNeil had his second straight three-hit game and fifth overall, raising his average to .340 as the Mets took two of three.

Mets manager Mickey Callaway decided just before a 27-minute rain delay at the start that he wouldn’t pitch deGrom.

“We kind of approached Jacob about it, said, hey, there’s a good chance you could start this game and it could be one inning or two innings. We could get a long delay and probably bang for the rest of the day,” Callaway said.

Making his ninth start, Oswalt allowed his 13th home run in 53 innings. Hoskins went deep for the third straight game and reached 30 for the first time.

Velasquez (9-11) gave up Amed Rosario’s eighth triple of the season leading off the bottom half, and Conforto followed with a run-scoring infield single — ending Velasquez’s streak of 14 consecutive scoreless first innings.

Dropping to 1-3 in his last six starts, Velasquez failed to get an out in the fifth. Pinch-hitter Dominic Smith doubled, Rosario was hit by an 0-2 pitch, McNeil lashed a tying opposite-field single to left and Conforto drove the next pitch for his 23rd homer, an opposite-field shot just over the left-field wall. The ball originally was called a double but was changed after a review of less than a minute.

Velasquez thinks the Phillies are lucky to still have a chance to reach the postseason.

“With us being the young team that we are, no one expected us to go this far,” he said. “I think all of us as individuals are pretty content in where we are right now, but we’re capable of doing a lot more and doing better.”

In a game played before what appeared to be fewer than 10,000 fans from an announced crowd of 24,153, rookie Drew Gagnon (1-1) pitched two hitless innings for the win in his first big league appearance since his debut against the Phillies on July 10.

Wilson Ramos had a sacrifice fly off Drew Smith in the sixth, but Austin Jackson restored a three-run lead with an RBI double in the seventh against Hector Neris. Four Mets pitchers combined for two-hit relief over six innings; Seth Lugo got six outs for his second save, allowing Carlos Santana’s two-out homer in the ninth.

“We’re still well within striking distance,” Hoskins said before heading to a nine-game homestand at Citizens Bank Park, where the Phillies are 43-26. “I still think there’s good baseball ahead of us.”

GLOVE GEM

Conforto reached into the left-field seats to grab Santana’s flyout for the final out of the sixth, stranding a pair of runners.

BEEN A LONG TIME

Hoskins is the first Philadelphia player to reach 30 homers since Ryan Howard in 2011.

SPUTTERING OFFENSE

Before Saturday’s 10-5 win, the Mets had averaged 2.9 runs in their previous 50 games at Citi Field, their lowest over a 50-game span at home since 1976, according to the Elias Sports Bureau.

TRAINER’S ROOM

Mets: RHP Noah Syndergaard had a red mark on his right side from Carlos Hernandez’s line drive Saturday night but said he will be good to take his next scheduled turn in the rotation. The ball missed hitting any ribs, instead landing on the fleshy part of his right side.

UP NEXT

Phillies: RHP Jake Arrieta (10-9) is scheduled for Monday’s opener versus Washington and RHP Tanner Roark (8-15). Arrieta won at Miami on Sept. 4, ending a five-start winless streak that included three losses.

Mets: deGrom was pushed back to Monday’s series opener against Miami and rookie RHP Jeff Brigham (0-1). DeGrom has made 25 consecutive starts overall allowing three runs or fewer, tying the major league record set by King Cole of the 1910 Chicago Cubs, yet he is 8-8 despite a 1.68 ERA.

(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)