Johan Santana doesn't think umpire C.B. Bucknor gave him a fair chance to beat the Atlanta Braves.
"We felt that we threw good pitches and didn't get the call," he said. "It's tough when you have a game like this and one pitch could be the difference in the game."
Ben Sheets pitched six scoreless innings in his first game in two years and the New York Mets lost 6-1 on Sunday for their.
Freddie Freeman hit a three-run homer in a six-run fifth inning and Sheets (1-0) allowed two hits and one walk with five strikeouts in his first start since July 19, 2010.
The Mets have lost four straight and seven of 10. Atlanta, which has won a season-high seven straight, improved to a season-high 10 games over .500.
Santana (6-6) gave up eight hits, six runs, two walks and struck out three in five innings.
"In his defense, he felt like he could've had two guys struck out in the inning," New York manager Terry Collins said. "Anybody who competes and things don't go your way, you're going to be upset. That's just the way it is.
The Braves had placed just two runners in scoring position before Matt Diaz, who began the game with a .514 in 35 career at-bats against Santana, doubled to lead off the fifth.
After Paul Janish walked on a slider that appeared to cross the outside part of the plate for a strikeout, Bourn hit a one-out, opposite-field RBI double down the line in left to score Diaz from second and make it 1-0.
Mets pitching coach Dan Warthen was ejected during a mound visit following Bourn's hit. When plate umpire C.B. Bucknor reached the mound, Warthen began arguing with him, apparently because Bucknor called Santana's sinker outside on a pitch that preceded Bourn's double with two strikes.
New York manager Terry Collins, who was ejected the day before, came on the field and spoke with crew chief Dale Scott near the third-base line, but walked back to dugout without further argument.
Collins said Warthen was furious.
"He takes pride in his pitchers," Collins said. "He takes pride in what they do and how they do it. When you make big pitches to get yourself out of trouble and you don't get them, he takes it personally."
Martin Prado followed with a sacrifice fly RBI to score Janish, and Bourn crossed the plate from third on Jason Heyward's RBI single. After Chipper Jones singled, Freeman hit his 12th homer to give the Braves a 6-0 lead.
"It was frustration," New York catcher Josh Thole said. "It was big pitches. You throw a backdoor slider (to Janish) there. It stays on the plate, and you get a ball. You punch him out right there. It changed the course of the game."
Ramon Ramirez and Miguel Batista pitched the last three innings for New York.
Kris Medlen replaced Sheets and gave up Andres Torres' RBI single to make it 6-1 in the seventh. Eric O'Flaherty got the third out of the eighth, and Anthony Varvaro pitched a scoreless ninth for Atlanta.
Sheets, unsigned after he missed all of 2011 following elbow ligament replacement surgery, escaped a jam in the third with runners on second and third when David Wright flew out to deep right.
Sheets threw 88 pitches, 57 for strikes. In his previous start two years ago, he lost 2-1 to Boston while pitching for Oakland.
Making his 242nd career start, Sheets improved to 91-92 and lowered his ERA to 3.77. Against the Mets, Sheets improved to 5-2 with a 4.05 ERA. The Braves purchased the former Milwaukee ace's contract from Double-A Mississippi before the game.
"I've been feeling like I can throw the ball where I want it," Sheets said. "That's the most important thing."
Santana hadn't pitched since twisting his right ankle while covering first base in an 8-7 loss to the Chicago Cubs on July 6.
Since throwing the Mets' first no-hitter on June 1 against St. Louis, Santana dropped to 3-4 with a 5.45 ERA in his last seven starts. He has given up 11 homers over that span.
Santana, who hasn't gotten a win against the Braves since Sept. 2, 2010, had the shortest start of his career, 1 1-3 innings, in a 9-3 loss at Turner Field on April 17.
"We knew coming into here that every game is important, especially coming into Atlanta and then (going to NL East-leading) Washington," Santana said. "If we compete, we're right there. It's tough."
NOTES: Santana threw 95 pitches, 56 for strikes. It was the third time in seven starts that Santana has allowed at least six runs. ... Mets RF Lucas Duda will have his left hamstring examined by a doctor in New York on Monday. He was held out of the lineup for the second straight game. ... Janish, who was acquired in a Saturday trade with Cincinnati, played in the majors for the first time this season. The 29-year-old spent the last 3½ months at Triple-A Louisville. ... Prado made his first start at 2B since 2009. ... Braves manager Fredi Gonzalez said RHP Randall Delgado will be recalled Saturday to start one of the Braves' doubleheader games at Washington. Delgado was optioned to Triple-A Gwinnett to make room on the roster for Sheets. ... Atlanta placed SS Jack Wilson on the DL to make room for Janish.