Jurrjens worked eight innings, extending his scoreless innings streak to 21 2-3, and Mark Teixeira backed him with a homer and three RBIs as the Braves beat the Toronto Blue Jays 4-0.
"He couldn't have pitched better than that," Cox said. "That's one of the best games I've seen pitched, ever."
Jurrjens (8-3) allowed just three hits - all singles - and didn't allow a runner to reach second base. He turned it over to Mike Gonzalez for the ninth.
"All of his other ones have been on the great side," Cox said. "This is on the excellent side. His location was just perfect."
Teixeira also recognized that he was watching something special.
"JJ was awesome tonight," Teixeira said. "He was real close to throwing a no-hitter."
He did a real good job of staying down in the zone," Teixeira continued. "He didn't go out there and try to strike everybody out. He was letting guys hit the ball and getting double-play balls, getting ground balls. They weren't hitting much hard."
Jurrjens walked one and struck out three. Fifteen of the 24 outs he recorded came on ground balls.
"The two-seamer was really working today," Jurrjens said. "I kept throwing it and throwing it and they kept hitting it into the ground."
Atlanta posted just its 12th road victory of the season, the lowest total in baseball, while Toronto was blanked for the sixth time this season and second time in seven games.
Jurrjens retired the first 13 batters in order before Matt Stairs grounded a single up the middle in the fifth. Scott Rolen promptly ended the inning by hitting into a double play.
The 22-year-old rookie didn't allow another hit until the seventh, when third baseman Ruben Gotay dove to grab a sharp grounder by Alex Rios, but threw late to first. Vernon Wells bounced back to the mound for the third out.
"He didn't really make too many mistakes," Wells said. "He was living on the edges, living down in the zone. He did his job and kept us off balance."
Jurrjens, who won his fourth straight decision, leads major league rookies in victories and has not lost since May 12 at Pittsburgh, a span of nine starts.
Jurrjens has not allowed an earned run in his past three appearances.
"I wasn't trying to blow it by every batter," Jurrjens said. "I was just pitching to contact and trying to save some pitches because pitching in the American League is different. In the National League, you have the pitcher in there and you can mess around a little bit, but not in the American League."
