NEW YORK -- Lucas Sims had a day to remember on the mound and at the plate Monday afternoon, when the Atlanta Braves rookie right-hander earned the win in a 9-2 victory over the New York Mets in the opener of a doubleheader at Citi Field.

Sims tossed 6 2/3 strong innings and collected his first major league hit to start a three-run sixth.

The Braves (71-84) have won four of five while the Mets (66-90) have lost three straight and 11 of 14. The 90-loss season is the first for New York since 2009.

The 6 2/3 innings were a career high for Sims (3-5), who allowed two runs on five hits and two walks while striking out six in his first start since Sept. 2. He carried a four-hit shutout into the seventh and was lifted with two on and two outs before Dan Winkler gave up a two-run double to Tomas Nido.

Another rookie, second baseman Ozzie Albies, gave the Braves the lead with a homer leading off the fourth. Sims, who was hitless in his first 12 big league at-bats, led off the sixth with a single before Ender Inciarte and Albies drew walks to chase Mets starter Chris Flexen.

One out later, Nick Markakis hit a two-run double. After an intentional walk to Tyler Flowers, Rio Ruiz lofted a sacrifice fly to extend Atlanta's lead to 4-0.

Inciarte laced an RBI double in the seventh before Flowers (two-run homer) and pinch-hitter Matt Adams (RBI single) added some insurance in the eighth for the Braves, who received one hit apiece from 10 different players. Ruiz delivered another sacrifice fly in the ninth.

Juan Lagares had three hits for the Mets.

Flexen (3-5) allowed four runs on three hits and three walks while striking out four over five-plus innings.

NOTES: The doubleheader was necessitated by a rainout at Citi Field on April 25. ... Mets 1B Dominic Smith was named the organization's minor league player of the year. Smith hit .330 with 16 homers and 76 RBIs in 114 games for Triple-A Las Vegas before being promoted to the majors Aug. 11. ... Braves manager Brian Snitker said RHP Michael Foltynewicz (cut right index finger) likely won't pitch again this season.