NEW YORK -- Jeff McNeil laced his second go-ahead hit in two days Monday night, when his RBI double in the fifth inning sent the New York Mets to a 1-0 victory over the Atlanta Braves and a doubleheader split.
Kyle Muller threw five sharp innings to earn his second big league victory in the opener, a 2-0 win for the Braves.
Under pandemic rules, each game was shortened to seven innings.
The Mets have split nine of their 11 doubleheaders this season and swept the other two. The loss in the nightcap prevented the third-place Braves (49-51), who have yet to be above .500 this year, from reaching the break-even mark for the seventh time. They are five games behind the NL East-leading Mets.
New York squandered a first-and-third, none-out opportunity in the fourth before scoring its lone run of the day in the fifth. Brandon Nimmo led off with an infield single and scored one out later on the double by McNeil, who was making his first start since Wednesday.
McNeil missed games Friday and Saturday against Toronto with left leg fatigue before delivering a pinch-hit, two-run double that broke a tie in the sixth inning of Sunday's 5-4 win.
Trevor May (3-2), the fourth of six Mets pitchers Monday night, threw a perfect fifth.
The Braves mounted their biggest threat in the sixth against Seth Lugo, who gave up a single to Joc Pederson and walked Ozzie Albies before Freddie Freeman flied out to the wall in left field. Austin Riley then hit into a 4-6-3 double play.
Edwin Diaz struck out the side in a perfect seventh for his 22nd save.
Braves starter Bryse Wilson allowed 4 hits and walked 1 with 2 strikeouts in 3-plus innings.
In the first game, the 23-year-old Muller (2-3) gave up 4 hits and walked 2 while striking out 3. He allowed the Mets to advance just two runners as far as second base as he lowered his ERA to 2.55 in six games (five starts).
Muller also helped build the Braves' first run by singling off Marcus Stroman (7-9) in the third for his first major league hit. Pederson followed with an RBI double.
An unusual double by Dansby Swanson leading off the fourth began the Braves' second run-scoring rally. Swanson's shot high off the center-field wall was initially ruled a homer by second base umpire Jose Navas, but Kevin Pillar threw the ball into the infield and Swanson was tagged by shortstop Jonathan Villar as crew chief Doug Eddings overruled Navas and awarded Swanson second base.
Stephen Vogt followed with a single and Swanson scored when Orlando Arcia beat out a potential double-play grounder.
PHILLIES 6, NATIONALS 5 Andrew McCutchen hit a three-run homer in the bottom of the ninth inning to give the Philadelphia Phillies a victory over the sinking Washington Nationals. Rhys Hoskins also had a three-run homer for the second-place Phillies, who are 3 1/2 games behind the New York Mets in the NL East.
CUBS 6, REDS 5 Pinch-hitter Javier Baez hit a bases-loaded single in the bottom of the ninth inning to give the Chicago Cubs a win over the Cincinnati Reds. Anthony Rizzo homered in his second straight game for the Cubs. Joey Votto homered for the third time in three games and drove in three runs for Cincinnati, which dropped its second consecutive and lost for the seventh time in 10 games
RED SOX 5, BLUE JAYS 4 Alex Verdugo hit a two-run homer in the eighth inning and the AL East-leading Boston Red Sox rallied late for the second straight game, beating Toronto in the opener of an important series for the Blue Jays. Boston star Rafael Devers added a solo homer on the four-year anniversary of his first major-league shot. Adam Ottavino (3-3) worked a scoreless inning for the win. Matt Barnes got the final three outs for his 22nd save.
ROYALS 4, WHITE SOX 3 Jorge Soler hit two home runs for the second consecutive game and the Kansas City Royals extended their winning streak to six games with a victory over the Chicago White Sox. Mike Minor (8-8) gave the Royals their fifth quality start in the last six games. He allowed 2 runs on 3 hits over 6 innings. He walked two and struck out seven. Minor's victory in Milwaukee on July 20 started the Royals' current winning streak. Former University of Arkansas pitcher Dallas Keuchel (7-4) took the loss after surrendering three solo home runs. He allowed 4 runs on 6 hits over 6 innings.
TWINS 6, TIGERS 5 (10) Max Kepler's RBI single in the bottom of the 10th inning against All-Star closer Gregory Soto gave the Minnesota Twins a victory over the Detroit Tigers. Soto walked the bases loaded in the ninth before striking out Willians Astudillo on three pitches, finishing him with a 100 mph fastball. Soto had two outs in the 10th, but walked Andrelton Simmons and then gave up Kepler's ninth career game-ending hit.