Omar Infante drove in the go-ahead run with a 10th-inning double and Brian McCann added a grand slam later in the inning to give Atlanta an 8-2 win over the Astros on Wednesday.
"It was a good series," Cox said. "We took it. That's all you can ask. A sweep would have been great, but we almost got swept ourselves."
Infante's hit bounced low on the wall in left field and scored Rick Ankiel to put Atlanta back on top 3-2, giving closer Billy Wagner (6-2) the win after he blew a save in the ninth. Brandon Lyon (6-5) intentionally walked Melky Cabrera to set up a run-scoring single by Alex Gonzalez, and McCann's pinch-hit slam off Jeff Fulchino put the game out of reach.
The Braves trailed 2-1 on Tuesday night, but won 4-2 after a pair of homers in the ninth.
"As long as our team is winning ... that's what it's all about," said Wagner, the former Astros pitcher who will retire after this season. "That's not how I guess you'd draw it up, but you don't have much you can do about it. But a win's a win and it's good for us."
Braves starter Tommy Hanson gave up two hits and didn't allow an earned run before being replaced by Jonny Venters. He walked one in a scoreless eighth before Wagner took over.
Hunter Pence tied it 2-2 when he scored on a sacrifice fly by Chris Johnson off Wagner in the ninth inning. Pence singled on a grounder to third base before advancing to third on a single by Lee. Wagner retired the next two batters to send the game to extra innings.
Ankiel walked with one out in the 10th before reaching second on an error by Pedro Feliz, who couldn't handle the throw to first base. Lyon intentionally walked Eric Hinske before Infante's go-ahead hit and the flood of runs that followed.
"I didn't make good pitches and they hit them," Lyon said. "I just have to come back next time and make better pitches."
Houston closer Matt Lindstrom wasn't available Wednesday after pitching two days in a row and dealing with a sore back.
Hanson didn't allow a hit until Michael Bourn's single leading off the fourth.
Bourn stole second and tried to steal third, but got caught in a run down. Hanson dropped the throw while covering the base, though, allowing Bourn to return safely to second.
"One of the most amazing things to see is Bourn in the run down," Pence said. "Typically, for anyone that is human and not Superman, when they get in a run down, they're generally out."
Bourn stole third anyway and scored on a single by Pence to make it 1-1.