Kelly Johnson and Edgar Renteria singled for Atlanta in the seventh and were running on a 3-2 pitch when Tulowitzki caught Chipper Jones' line drive behind second base. The rookie stepped on the bag to double up Johnson and then tagged Renteria for the third out.
Apparently unsure if he had completed the play properly, Tulowitzki went back and touched second again, then threw to first. Nothing to worry about - the inning was already over.
"It's amazing," Tulowitzki said. "It kind of just fell in my lap."
It was the 13th unassisted triple play in major league history and first since Rafael Furcal did it for the Braves on Sept. 10, 2003, against the Cardinals.
It also was the second triple play in the Rockies' 13-year history. The first happened April 10, 2003, against St. Louis.
Philadelphia turned the only other triple play in the majors this season against Cincinnati on April 21.
The Rockies rallied to avoid a three-game sweep. They scored twice in the ninth against closer Bob Wickman to tie it at 7. Holliday had an RBI infield single and Brad Hawpe drove in the tying run with a groundout.
Todd Helton drew his club-record fifth walk from Steve Colyer (0-1) in the 11th before Holliday homered to center. Denny Bautista (1-0) worked a scoreless inning for the win.
Scott Thorman was 4-for-4 with his second homer of the year and an intentional walk. He had a two-run single in the three-run sixth inning when the Braves tied the game at 5.
SAN DIEGO - Brady Clark hit a go-ahead double in the 17th inning and Los Angeles beat San Diego in the longest game in Petco Park's four-year history.
It also was the longest game in the major leagues this season by innings and time - 4 hours, 55 minutes.
Clark's double off rookie Justin Hampson scored Wilson Valdez from first base with an unearned run. Valdez reached on a bunt when Pete Laforest, a third-string catcher who was playing first base, committed an error by letting a throw from catcher Rob Bowen hit off the top of his glove.
Jeff Kent and Luis Gonzalez hit consecutive homers off David Wells in the third to give the Dodgers a 4-1 lead. The Padres tied it in the seventh on Marcus Giles' RBI single.
The Dodgers took two of three in the series and have beaten the two-time defending NL West champions four times in six games this season.
Chad Billingsley (2-0) pitched two innings for the win. Hampson (0-1) worked the final four innings.
PHILADELPHIA - Jamie Moyer took a no-hit bid into the seventh inning and combined with two relievers for a four-hitter in Philadelphia's win over Florida.
Moyer had faced the minimum 20 batters when Miguel Cabrera broke up the no-hitter with a two-out double in the seventh.
The 44-year-old Moyer (3-1) allowed two hits, struck out five and walked two in 7 1-3 shutout innings. He also went 2-for-3 with a double.
Jayson Werth made a key defensive play in left field and had a two-run single for the Phillies, who have won seven of nine.
Wes Obermueller (1-1) gave up three runs and five hits in 5 2-3 innings.
WASHINGTON - John Maine pitched seven sharp innings and Carlos Beltran homered for one of New York's three hits against Washington.
Maine (4-0) struck out a career-high eight and allowed three hits in lowering his ERA to 1.35.
Aaron Heilman, Scott Schoeneweis and Billy Wagner finished the six-hitter. Schoeneweis got out of a two-out, bases- loaded jam in the eighth by getting Ryan Church to ground out to first, and Wagner pitched the ninth for his fourth save in four chances.
Beltran's fifth homer came off starter Jason Bergmann (0-2) in the sixth.
HOUSTON - Geoff Jenkins homered and Claudio Vargas pitched out of bases-loaded jams in three straight innings to lead Milwaukee past Houston.
Tony Graffanino and J.J. Hardy also drove in runs for the Brewers, who won a three-game series in Houston for the first time since 1997, when the Astros still played in the Astrodome.
Vargas (2-0) gave up four hits and five walks in five shutout innings, toughening up whenever the Astros threatened to score. Francisco Cordero shut out Houston in the ninth for his 10th save in 10 chances.
The Brewers have won eight of 11.
Woody Williams (0-4) allowed three runs and five hits in six innings for the Astros, who have lost eight of nine.
PITTSBURGH - Edwin Encarnacion's bases-loaded triple keyed Cincinnati's comeback from an early three-run deficit, and Aaron Harang settled down to maintain his dominance of Pittsburgh.
Adam Dunn added a two-run homer and Brandon Phillips drove in two runs for the Reds, who won the final two games of the series.
Harang (4-0) benefited from the offensive support, even contributing a run-scoring single in a five-run fourth that turned a 4-1 Reds deficit into a 6-4 lead. The big inning came against Paul Maholm (1-3), who was coming off a three-hit shutout of Houston.
PHOENIX - Orlando Hudson hit a tiebreaking, two-run double in the seventh inning and Arizona beat San Francisco for its fifth straight victory.
Hudson had three RBIs and Brandon Medders (1-0) earned the win with a scoreless seventh. Brandon Lyon escaped a bases-loaded, one-out jam for his first save.
Randy Johnson, making his second start since October back surgery, allowed three runs - two earned - and seven hits in six innings for the Diamondbacks.
The Giants had won eight straight entering the series.
Matt Morris (3-1) gave up 12 hits and five runs in seven innings.