"When he gets hot like this it's really, really something to watch," manager Fredi Gonzalez said. "Hopefully this is the beginning of one of those big runs that he can give us."
Upton is hitting just .185 this month, but his average for the season is .272 after a great start to the year.
"I'm seeing the ball and hitting it, that's about it," Upton said. "I've gotten some good pitches to hit and I've put good swings on them."
The Braves had just two hits when Upton launched his 16th homer, a two-run shot into the bullpen in right-center, to make it 3-0 in the seventh inning. Collin McHugh (4-6) had plunked Jason Heyward to set up things for Upton.
Upton drove in Atlanta's first run on a sacrifice fly in the second inning. He joked that Wood owed him a treat of some kind for providing most of the offense in the win.
"Just maybe get an ice cream cone or something," Upton said with a laugh. "They've got some good ice cream in there, at least get a scoop of ice cream."
Braves first baseman Freddie Freeman left in the eighth after being hit by a pitch on what appeared to be his right elbow. He was examined by a doctor, and said he was fine and that he hoped the swelling wouldn't be too bad Thursday so he could play.
"I needed to get ice on it with a day game tomorrow, so I just tried to keep the swelling down, see if I can go tomorrow," Freeman said, according to the Atlanta Journal-Constitution. "The doctor already saw me. Everything is good. Hopefully it's not too swollen and too sore tomorrow to go. But I'm going to try to do everything I can to."
Wood (6-6) was recalled from Triple-A Gwinnett to make his first start since May 4 after appearing in 11 games out of the bullpen in his last stint with the Braves. He allowed three hits and struck out four with one walk.
"He did a nice job," Gonzalez said. "Mixed all his pitches ... his breaking ball, his fastball, threw some nice change ups."
Gonzalez was encouraged by Wood's performance in filling in for Gavin Floyd, who had surgery this week after breaking a bone in his throwing elbow.
Simmons and Jaime struck out two apiece in a hitless inning apiece.
McHugh struck out nine in his third straight loss.
"He made a mistake to a really good hitter, and he didn't miss it," manager Bo Porter said of Upton's homer. "But outside of that one pitch, I feel like he was in complete control of the game the entire time."
Evan Gattis doubled to start the second and scored on the one-out sacrifice fly by Justin Upton.
McHugh walked a pair in the fourth inning, but the Braves didn't get another hit until Freeman singled with two outs in the sixth. Freeman was tagged out trying to stretch it into a double to end the inning.
Dexter Fowler hit a leadoff double in the first, and was thrown out at third trying to advance on Jose Altuve's grounder. Houston didn't get another runner until rookie Jon Singleton snapped an 0-for-17 skid with a ground-rule double to right-center field with two outs in the fourth.
The ball got lodged under the wall and Singleton was already heading toward home when he was called back to second base.
Wood got right back on track after Singleton's hit and set down the next five Astros before walking Fowler with one out in the sixth. George Springer singled with two outs to put runners at the corners, but Wood struck out Singleton to escape the jam.
Braves LHP Ryan Buchter was optioned to Gwinnett to make room for Wood on the roster. ... The Astros recalled OF L.J. Hoes from Triple-A Oklahoma City and optioned OF Robbie Grossman there before the game. ... Atlanta RHP David Carpenter, on the disabled list with a strained right biceps, felt good after throwing a bullpen on Tuesday and is scheduled to throw another one on Thursday. ... SS Carlos Correa, Houston's top prospect and the No. 1 overall pick in the 2012 draft, had season-ending surgery on Wednesday after breaking his right fibula.
The Associated Press contributed to this report.