Making his Braves' debut, Harang gave up two hits in 6 2-3 innings, struck out three and walked one.
Relievers Luis Avilan, David Carpenter and Craig Kimbrel were hitless, with Kimbrel getting three outs for his second save.
Garza (0-1) made his Milwaukee debut after signing a $50 million, four-year contract as a free agent. He allowed one run and two hits in eight innings, struck out seven and walked none.
PIRATES 4, CUBS 3, 16 INNINGS
PITTSBURGH • In a game that took 5 hours, 55 minutes, pinch-hitter Tony Sanchez singled in the winning run in the bottom of the 16th inning to give the Pirates a victory over the Cubs the longest game in Pittsburgh history by time.
Sanchez's hit came off Carlos Villanueva (0-2), ending the game just short of 1 a.m. and 6 minutes longer the Pirates 8-7, 18-inning victory over Houston on May 27, 2006, that took 5:49.
Jordy Mercer opened the 16th with a bunt single but was forced out at second on Jose Tabata's sacrifice attempt. Starling Marte followed with a singled to put runners on corners before Sanchez, the rookie catcher and last position player left on the Pirates' bench, grounded into left field for the walkoff hit.
NATIONALS 5, METS 1
NEW YORK • Gio Gonzalez homered in his first start for the second straight season and pitched three-hit ball to lead the Nationals over the Mets.
Ian Desmond also went deep and Jayson Werth had four hits for the Nationals, who followed up their 10-inning comeback on opening day with a more routine victory against one of Gonzalez's favorite foes. The left-hander struck out six and walked one in six comfortable innings, improving to 6-0 in his last seven starts against New York.
Bartolo Colon (0-1) was touched up for nine hits over six innings in his Mets debut.
Desmond and Gonzalez (1-0) both homered in the fifth against Colon.
ROCKIES 6, MARLINS 5
MIAMI • Jordan Pacheco had three hits, Jordan Lyles won in his Colorado debut as the Rockies held on for a victory over the Marlins for their first win of the season.
Charlie Blackmon and Michael Cuddyer each had two hits and an RBI for Colorado, which lost the first two games of the season-opening series.
Giancarlo Stanton hit a two-run homer and drove in three runs, all after Miami fell behind 6-1.
Lyles (1-0) was acquired in an offseason trade the sent Dexter Fowler to the Houston Astros. Lyles allowed four runs and five hits in five innings while striking out five and walking one.
REDS 1, CARDINALS 0
CINCINNATI • Chris Heisey's single in the bottom of the ninth inning ended Cincinnati's record scoreless streak to open a season and sent the Reds to a victory over the Cardinals following a long rain delay.
Ryan Ludwick and Todd Frazier opened the ninth with singles off Carlos Martinez (0-1). After a sacrifice, Brayan Pena was walked to load the bases and the pinch-hitting Heisey singled up the middle.
The Reds were the last team in the majors to score a run this season. Heisey's hit broke an 0 for 11 slump with runners in scoring position.
J.J. Hoover (1-0) pitched out of a threat in the ninth, getting Matt Adams on a called third strike with two runners aboard.
DODGERS 5, PADRES 1
SAN DIEGO • Hanley Ramirez hit a two-run double in the first inning and Dan Haren pitched six strong innings to lead Los Angeles.
The Dodgers took two of three from the Padres and now play their home opener Friday afternoon against San Francisco. The Dodgers have already played the regular-season opener against Arizona in Sydney and played in the North American opener against the Padres Sunday night.
Haren retired the first nine batters before Everth Cabrera singled to center leading off the fourth and eventually scored on Yonder Alonso's one-out single to right.
Haren (1-0) allowed four hits, struck out seven and walked none.
The Dodgers jumped on Tyson Ross (0-1) for three runs in the first inning.
GIANTS 2, DIAMONDBACKS 0
PHOENIX • Tim Hudson allowed three hits while working into the eighth inning in his first start for the Giants.
Hudson (1-0) was making his first start since July 24 after fracturing his right ankle against the Mets while pitching for the Braves. The veteran right-hander had four strikeouts and no walks, and had Arizona hitters pounding the ball into the ground.
Arizona starter Trevor Cahill (0-1) held the Giants scoreless until the fifth. Angel Pagan singled in a run in the fifth and Michael Morse doubled in a run in the sixth to make it 2-0.
Sergio Romo shut down the Diamondbacks in order to record his second save.