Upton hit his seventh home run of the season. Chris Johnson had four hits and two RBIs for the Braves, who took a 7-0 lead in the third inning against Gio Gonzalez (1-1).
In sweeping their NL East rivals and compiling the best record in the major leagues, Atlanta (11-1) has outscored the opposition 62-23.
Washington has lost seven straight to Atlanta since last year.
Maholm (3-0) allowed four hits in 7 2-3 innings. He has not permitted a run this season in 20 1-3 innings over three starts.
PHILLIES 2, MARLINS 1
MIAMI (AP) — Roy Halladay earned his 200th career victory, bouncing back from consecutive poor outings to pitch eight innings and help the Philadelphia Phillies beat the Miami Marlins 2-1.
Laynce Nix broke a 1-all tie with his second pinch-hit homer of the season in the ninth.
Halladay (1-2) allowed five hits, walked one and lowered his ERA from 14.73 to 7.63. He's the 109th pitcher to reach the 200-win milestone, and the first to do so in a Phillies uniform since Hall of Famer Steve Carlton in 1978.
Nix batted for Halladay with one out in the ninth and homered into the upper deck in right field off Jon Rauch (0-2).
Jonathan Papelbon pitched around a leadoff walk in the ninth for his second save.
DIAMONDBACKS 1, DODGERS 0
PHOENIX (AP) — Paul Goldschmidt hit a game-winning single off Josh Beckett with one out in the ninth inning, lifting the Arizona Diamondbacks over the Los Angeles Dodgers.
Diamondbacks starter Trevor Cahill pitched six-hit ball for 7 1-3 innings. J.J. Putz (1-0) walked one in the ninth.
Beckett (0-2) gave up a one-out double to A.J. Pollock in the ninth. Beckett ran the count to 3-0 before intentionally walking Miguel Montero, and Goldschmidt singled to right field.
ROCKIES 2, PADRES 1
SAN DIEGO (AP) — Todd Helton had a pinch-hit, two-run homer in the seventh inning and Jorge De La Rosa and three relievers combined on a two-hitter to carry the Colorado Rockies over San Diego.
Colorado also swept San Diego at Coors Field last weekend.
Helton's homer off Dale Thayer (0-1) broke a scoreless tie. It was Helton's first homer this season and his third career pinch homer.
De La Rosa (1-1) held the Padres scoreless on two hits in six innings. Rafael Betancourt gave up a run in the ninth before getting his fifth save.
BREWERS 4, CARDINALS 3, 10 INNINGS
ST. LOUIS (AP) — Jonathan Lucroy hit a solo home run in the 10th inning as the Milwaukee Brewers rallied past the St. Louis Cardinals and avoided a sweep.
The Brewers had gone a team-record 32 innings without scoring before Ryan Braun hit a two-run homer off reliever Trevor Rosenthal in the eighth. Braun's second home run of the season snapped a 39-inning shutout streak for St. Louis pitchers.
Milwaukee tied it in the ninth on a leadoff single by Carlos Gomez and a double by Yuniesky Betancourt off Mitchell Boggs. Lucroy's first homer this year came off Fernando Salas (0-2).
Brandon Kintzler (1-0) pitched a scoreless ninth. Burke Badenhop got his first save.
Matt Adams homered for the third straight game for St. Louis.
GIANTS 10, CUBS 7, 10 INNINGS
CHICAGO (AP) — Edwin Jackson and Michael Bowden tied a major league record by combining to throw five wild pitches in an inning, and the San Francisco Giants beat the Chicago Cubs in the 10th.
The Cubs matched the record for wild pitches by a team in an inning during a four-run sixth.
Hunter Pence hit a tying homer with two outs in the Giants' ninth off Shawn Camp (0-1). A balk by Camp scored the go-ahead run in the 10th.
George Kontos (1-1) pitched a scoreless inning and Sergio Romo worked the 10th for his seventh save in eight chances.
PIRATES 10, REDS 7
PITTSBURGH (AP) — Backup catcher Michael McKenry had the first two-homer game of his four-year major league career, Starling Marte hit a tiebreaking two-run drive in a six-run eighth inning and the Pittsburgh Pirates sent Cincinnati to its fifth straight loss.
The Pirates swept the Reds for the first time since April 2010 in Pittsburgh.
Pittsburgh trailed 5-0 when McKenry homered off Mat Latos leading off the seventh. McKenry hit a tying homer in the eighth.
Jared Hughes (1-0) got the win and Jonathan Broxton (0-1) took the loss.