DENVER (AP) -- Feeling sluggish before the game, Colorado Rockies outfielder Jeffrey Hammonds just needed a little excitement to get his adrenaline going.

	Todd Helton tied things up with this ninth-inning homer, then the Rockies won it 5-4.

After sliding underneath Tony Eusebio's tag attempt, Hammonds flipped head over heels in the dirt before being mobbed by his jubilant teammates.

"These games are more fun than 8-1," Hammonds said. "It keeps you in the game a lot longer."

Todd Helton, who had not homered since May 29, tied the game at 4 when he hit a 94 mph fastball from Billy Wagner (2-4) over the center-field fence leading off the ninth.

Hammonds followed with sharp single, advanced to second on a groundout and took third on a wild pitch. Mayne then hit a bouncing grounder to first baseman Jeff Bagwell, whose throw to the plate was high, allowing Hammonds to slide in safely under Eusebio's glove.

"It was do or die," Bagwell said. "I had to come and jump for it. I had to make a great throw and didn't get a very good grip on it."

Colorado's comeback prevented Houston from winning three straight for the first time this season and gave the Rockies some momentum as they prepare for a three-game series against NL West-leading Arizona.

"It picks us up for the weekend," Colorado manager Buddy Bell said. "I don't know if we necessarily needed it, but we'll take it. It's something that will help us get our hearts started."

Wagner, who had been 4-for-4 in save chances at Coors Field, blew a save opportunity for the eighth time in 14 chances. The Astros fell to 3-15 in one-run games.

"I don't have an answer to this," Wagner said. "What do you want me to do? Start making up pitches out there? I am throwing pitches and they aren't missing them."

Colorado closer Jose Jimenez (4-0) had his own problems, allowing a game-tying single to Bill Spiers in the ninth and forcing home the go-ahead run when he walked Richard Hidalgo with the bases loaded.

Helton bailed out Jimenez with his 18th home run of the season and his first in 48 at-bats.

"It seemed like about 248 at-bats," Helton said. "About two weeks ago, they started pitching me a little different, a little tougher. They were testing my discipline a little bit."

The Rockies had taken a 3-2 lead on Neifi Perez's RBI single off Marc Valdes in the eighth. The hit ended an 0-for-10 slide for Perez and came in his first pinch-hitting appearance since July 18, 1998.

"This was not atypical of the way we've played this year," Astros manager Larry Dierker said. "We have been unable to hold a lead so many times I can't even count them."

Colorado starter Kevin Jarvis gave up two runs and struck out a career-high seven in seven innings. Houston starter Octavio Dotel, winless in eight starts since May 1, gave up just three runs -- two earned -- and five hits in 6 1/3 innings.

Dotel left in the seventh after Helton scored from first to tie the game at 2 as left fielder Moises Alou mishandled a single by Hammonds.

"They had a great performance from Dotel," Hammonds said. "He was throwing that ball as well I've seen anyone all year."

Colorado took a 1-0 lead in the first when Tom Goodwin scored on a passed ball by Eusebio, but the Astros went ahead in the second on Hidalgo's solo homer and an RBI single by Craig Biggio.

Game notes
With victories Tuesday and Wednesday, Houston became just the second team to win a series against Colorado at Coors Field this season. The New York Mets are the other. ... Hammonds has hit in 14 straight. ... Alou went 0-for-5, ending his 12-game hitting streak.... Colorado has not lost three straight home games this year.