Coming off a 14-strikeout performance in a 3-0 loss to Philadelphia, deGrom became just the ninth pitcher to strike out as many as nine in a row.
The streak ended in the fifth inning, when the Rockies took a 3-1 lead with three unearned runs, but the Mets rallied to win a series opener delayed a day by snow when pinch-hitter Jonathan Villar hit a tying double off Daniel Bard (0-1) in the seventh inning and Dominic Smith had a sacrifice fly.
Pete Alonso had homered in the sixth to pull the Mets within a run.
By winning the opener of a doubleheader of seven-inning games under coronavirus protocols, the Mets extended a winning streak to four for the first time since 2019.
DeGrom (1-0) allowed three unearned runs and three hits in six innings and walked one, lowering his ERA to 0.45.
He started the streak with a called third strike against Josh Fuentes for the first out of the second inning, then got Sam Hillard and Dom Nunez swinging.
He struck out Chi Chi González, Raimel Tapia and Ryan McMahon in the third, and Trevor Story, Charlie Blackmon and C.J. Cron in the fourth.
Fuentes grounded an 0-1 pitch leading off the fifth and reached on a throwing error by second baseman Jeff McNeil, ending the streak.
Detroit reliever Tyler Alexander was the previous pitcher to strike out nine in a row, accomplishing the feat last Aug. 2 against Cincinnati.
Seaver set the record against San Diego on April 22, 1970, striking out his final 10 batters in a 19-strikeout performance.
Colorado took a 3-1 lead against deGrom later in the fifth when Nunez hit an RBI triple, pinch-hitter Yonathan Daza hit a sacrifice fly and Tapia homered. All three runs were unearned because of McNeil's error.
Despite deGrom's 2.06 ERA in 78 starts since the start of the 2018 season coming in, New York was 36-42 with him on the mound.
With nine strikeouts in a row, deGrom matched the New York Giants' Mickey Welch against Cleveland on Aug. 28, 1884, San Diego's Jake Peavy at Arizona on April 25, 2007, the Marlins' Ricky Nolasco at Atlanta on Sept. 30, 2009, the Los Angeles Dodgers' Aaron Harang against San Diego on April 13, 2012, Detroit's Doug Fister against Kansas City on Sept. 27, 2012, Washington's Max Scherzer against the Mets on Oc. 3, 2015, and Alexander.
DeGrom extended his road unbeaten streak to 17 with the 48th double-digit strikeout game for the two-time NL Cy Young Award winner.
Edwin Díaz struck out the side for his first save this season.
Mets: INF José Peraza was optioned to the alternate training site to clear a roster spot for J.D. Davis, who was activated from the 10-day injured list. Davis bruised his left hand when hit by a pitch April 6 against Philadelphia. RHP Franklyn Kilome was sent outright to the alternate training site.
RHP Marcus Stroman (2-0) starts for the Mets on Sunday and RHP Antonio Senzatela (1-2) for the Rockies.,
DeGrom fans 9 Rockies in a row on his way to 14-strikeout game
Jacob deGrom strikes out 14 batters in six innings of work vs. the Rockies.