Adam Wainwright earned the victory and recorded a career-high four RBIs to help St. Louis rout Colorado at Coors Field.
St. Louis are tied with the New York Mets for the top wild-card spot in the National League. San Francisco was a half-game back pending the outcome of their late game with the Los Angeles Dodgers.
Wainwright (12-9) worked 5 1/3 innings, the third time in four starts he failed to reach the sixth. He improved to 9-1 with a 1.70 ERA in 14 games (10 starts) versus the Rockies, 3-0, 2.73 in five games (four starts) in Denver.
Giants 2, Dodgers 0
Solo home runs by Eduardo Nunez in the fifth inning and Brandon Belt in the ninth held up as the San Francisco Giants defeated Los Angeles 2-0 on Tuesday night at Dodger Stadium.
San Francisco snapped a three-game losing streak, but it came with a price. Winning pitcher Johnny Cueto (17-5) left the game in the sixth inning with a groin strain, while standout shortstop Brandon Crawford is out with a fractured left pinky.
Cueto is listed as day-to-day, while there's not yet a timetable for Crawford.
The Giants (80-71) pulled into a three-way tie with St. Louis and the New York Mets for the two National League wild-card spots, and trail the Dodgers by five games in the West.
Braves 5, Mets 4
NEW YORK -- Julio Teheran continued his mastery of New York as the right-hander allowed one run over seven strong innings to lead Atlanta to its second straight victory over the Mets.
The National League wild card-leading Mets (80-71) entered Tuesday with a one-game lead over the San Francisco Giants and St. Louis Cardinals.
Teheran (6-10) allowed five hits and one walk while striking out one as his ERA against New York this season rose from 0.78 to 0.90. He is 7-3 with a 2.36 ERA in 15 career games (14 starts) versus the Mets.
Red Sox 5, Orioles 2
BALTIMORE -- David Ortiz got his 36th home run, a three-run shot in the seventh inning, and Boston extended its winning streak to six games with a victory over Baltimore at Camden Yards.
The Red Sox increased their lead over the Orioles to five games in the American League East. Baltimore lost three out of four, but still holds a narrow margin for one of the two wild-card spots.
Mookie Betts continued to pound Orioles' pitching and went 3-for-5 with two runs, while Jackie Bradley Jr. got his 26th homer.
Cubs 6, Reds 1
CHICAGO -- Jon Lester claimed his National League-leading 18th victory as Chicago beat Cincinnati at Wrigley Field.
Lester (18-4) allowed one run on six hits while striking out five and walking none in a seven-inning outing.
His 18 wins are the most since going 19-9 with the Red Sox in 2009.
Anthony Rizzo was 2-for-5 with three RBIs, Kris Bryant added three hits and Dexter Fowler reached base four times as the Cubs mounted a 11-hit attack.
Marlins 1, Nationals 0
MIAMI -- Jose Fernandez pitched eight scoreless innings, and Giancarlo Stanton hit a home run as Miami defeated Washington at Marlins Park.
The Nationals, till comfortably ahead in the NL East, lost four games in a row. The Marlins have been projected to have less than a one percent chance to make the playoffs as an NL wild-card team. They won three games in a row.
Fernandez struck out 12 and allowed just three hits and no walks. It was his ninth double-figure strikeout game of the season, and he retired 21 consecutive batters before running into trouble in the eighth.