Washington grabbed a six-game lead in the NL East, handing Atlanta its third straight loss.
Ian Desmond led off the 13th with an infield single off Cristhian Martinez (5-3) before Danny Espinosa tried to bunt and hit into a forceout. Kurt Suzuki then hit a slow roller for an infield hit, allowing Espinosa to take third.
With the infield in, Tracy hit a ball to Braves second baseman Dan Uggla, who appeared confused and instead of either trying to get Espinosa at the plate or attempting to turn a double play, he fumbled it, and Espinosa scored the game-winner.
Craig Stammen (6-1) pitched two hitless innings for the win.
PHILLIES 12, REDS 5
PHILADELPHIA (AP) — John Mayberry Jr. hit a two-run homer and Ryan Howard and Erik Kratz had solo shots to help Roy Halladay get the victory for Philadelphia.
Halladay (7-7) wasn't sharp, allowing five runs and 10 hits in seven innings. But the offence bailed out the two-time Cy Young Award winner.
Domonic Brown hit a go-ahead two-run double off Mike Leake (5-8) in a four-run fifth. Mayberry had three hits and three RBIs, and Chase Utley, Howard and Kratz each drove in two. Juan Pierre had three hits and scored three times.
The Phillies have won seven straight over the Reds and 12 of 13, dating to 2010. This was their first meeting this season.
The NL Central-leading Reds lost for just the third time in 11 games.
MARLINS 12, DIAMONDBACKS 3
PHOENIX (AP) — Giancarlo Stanton homered twice, including the first of back-to-back home runs during Miami's nine-run fourth inning.
Justin Ruggiano homered after Stanton, and Jose Reyes had four hits — including three doubles — scored twice and drove in a run for the Marlins, who have won three of four.
Miami's 10 hits in the fourth matched a franchise record set last September 9 at Pittsburgh and the 12 runs and 20 hits were season highs.
Mark Buehrle (11-11) was the beneficiary of the offence, allowing two runs and six hits over seven innings for his second straight win.
Arizona's Joe Saunders (6-10) gave up nine runs and 12 hits in 3 2-3 innings.
BREWERS 9, CUBS 5
MILWAUKEE (AP) — Jonathan Lucroy hit two home runs and the Brewers scored eight runs in the fifth inning to rally for the victory.
The Brewers sent 11 batters to the plate and recorded seven hits in their biggest inning since they scored nine times in the second in an 11-6 victory over the Los Angeles Dodgers on May 5, 2010.
The rally gave Mark Rogers (1-1) his first major league victory in seven career starts, including five this season. Rogers allowed three runs and five hits in five innings.
Justin Germano (2-3) yielded seven runs and eight hits in 4 2-3 innings in his fifth start for Chicago after being acquired from Boston on July 19 for cash.
Josh Vitters hit a solo drive in the fifth for his first career homer, extending the Cubs' lead to 3-1.
ROCKIES 3, METS 1
NEW YORK (AP) — Tyler Colvin hit a tying homer off R.A. Dickey in the fifth inning, then made a diving play in the eighth to help Colorado get the victory.
Jonathan Herrera bunted for a hit in the top of the eighth and made his way around the bases with help from some inept defence, putting the Rockies in front 2-1.
Colvin's first home run in 105 at-bats denied the knuckleballer a chance for his 16th win and helped the Rockies to their sixth victory in eight games.
Colvin made a lunging stop on pinch-hitter Jordany Valdespin's sharp grounder just inside the first-base bag with the bases loaded and his toss to Matt Belisle just beat a diving Valdespin to the bag. Valdespin jumped up, waving his arms in disbelief, and manager Terry Collins engaged first base umpire Lance Barksdale in a prolonged discussion.
Rex Brothers (7-2) got the win and Rafael Betancourt worked the ninth for his 24th save.
Josh Edgin (1-1) was charged with the loss.
GIANTS 2, DODGERS 1
LOS ANGELES (AP) — Madison Bumgarner scattered four hits over eight scoreless innings, Pablo Sandoval drove in both runs and the San Francisco Giants defeated the Los Angeles Dodgers 2-1 on Monday night to regain the NL West lead by a half-game.
Bumgarner (14-7) pitched his second scoreless outing of the season for the Giants, who have won six of their last nine games and 11 of 17.
They erased the Dodgers' half-game lead in a division race that has seen the rivals frequently swap leads.
Bumgarner struck out 10 and walked none to even his road record at 6-6.
Javier Lopez got the final out in the ninth to earn his second save in four chances.
The loss spoiled a solid outing by Clayton Kershaw (11-7), who gave up two runs and six hits in eight innings. The reigning NL Cy Young Award winner struck out 10 and walked none as his four-game winning streak ended.
PADRES 3, PIRATES 1
SAN DIEGO (AP) — Edinson Volquez struck out 10 and Will Venable drove in two runs to lift the San Diego Padres to a 3-1 victory over the Pittsburgh Pirates on Monday night.
The loss comes on the heels of Pittsburgh's 19-inning 6-3 victory at St. Louis on Sunday afternoon.
San Diego, which snapped a five-game losing streak Sunday, has won 16 of 19 against the Pirates. Pittsburgh is a half-game ahead of the Los Angeles Dodgers for the final wild-card berth.
Volquez (8-9), who had a 13.83 ERA in his previous four starts, allowed one run and five hits. The right-hander walked three and hit a batter.
It was the first time Volquez has pitched past the fourth inning in four starts this month.
Kevin Correia (9-8) started in place of scheduled starter Wandy Rodriguez despite throwing 24 pitches in two shutout innings on Sunday. On a 75-pitch limit, he gave up three runs — two earned — and seven hits in 4 1/3 innings.