By ARNIE STAPLETON
AP Sports Writer

DENVER(AP) -- The Colorado Rockies' celebration over Jason
Giambi's heroics quickly turned to concern over closer Huston
Street's ailing right arm.

Giambi's pinch-hit two-run single off Brian Stokes broke an
eighth-inning tie and powered the Rockies to a 5-2 win over the
New York Mets on Wednesday night.

But the crowd's cheers quieted when left-handed setup man
Franklin Morales jogged out from the bullpen instead of Street,
who has 33 saves in 34 chances.

"He has a little tightness in his biceps area," Rockies manager
Jim Tracy explained. "It was a little bit tight last night and
it wasn't loosening up real good while we were rallying in the
eighth inning."

So, Franklin pitched the ninth for his first career save instead
of Street, who said he initially blamed the tightness Tuesday
night on having not pitched in a week.

"I didn't like the decision, but it was the right call," said
Street, who had ice packs and a muscle stimulator on his biceps
after the game.

"This late in the season you can't afford to mess up and be down
two or three weeks when it might be only four or five days to a
week if we just be smart about it and shut it down."

Street said he hasn't had this kind of injury since high school
but was confident that he was avoiding a longer layoff by not
trying to work through the injury.

Giambi's first hit for the Rockies made a winner of Ubaldo
Jimenez, who outdueled Tim Redding and kept Colorado atop the NL
wild-card race by a game over San Francisco.

"That's one of the reasons I came here, to help this team down
the stretch," Giambi said.

With the bases full and the crowd on its feet waving white
giveaway T-shirts, Giambi, pinch-hitting for Clint Barmes, lined
Stokes' first offering into center field just over the
outstretched glove of a leaping shortstop Anderson Hernandez
near the second base bag, making it 4-2.

"We had him played just right. Our shortstop wasn't tall
enough," Mets manager Jerry Manuel said.

Giambi, who was jettisoned by Oakland this summer, signed with
Colorado last week and was called up from the minor leagues
Tuesday for just these kinds of circumstances. On Tuesday night,
he walked on four pitches with the bases full. This time, he
didn't hesitate to jump on the first strike he saw.

"I've seen him do that too many times," said Mets outfielder
Gary Sheffield, who played with Giambi on the Yankees from
2004-06. "He's a professional hitter. He doesn't panic in those
situations."

Giambi has said he doesn't mind going from full-time slugger to
part-time player, one who's called upon for his clubhouse
leadership as much as his late-inning at-bats.

"It's kind of a new experience for me, but at the same time I
enjoy being in that spot," said the 38-year-old veteran. "I'm
thankful that the Rockies came calling and gave me this
opportunity. ... Like I said, there are no small roles in a
chance to win a pennant."

Yorvit Torrealba followed Giambi's electrifying moment with a
run-scoring single off Stokes (2-4), extending his career-best
hitting streak to 12 games.

Jimenez (13-10), who went 5-1 with a 1.77 ERA in August, allowed
two earned runs on five hits in eight spectacular innings as he
worked at least into the sixth for the 24th straight time - and
got the win to show for it thanks to Giambi.

"I knew he would deliver," Jimenez said. "I knew he would come
through and he did."

Giambi has just as much praise for Jimenez, whose only mistake
was a hanging curve that Jeff Francoeur deposited over the
left-field wall in the second inning, his 12th homer tying the
game at 2.

"You're looking at a future Cy Young winner," Giambi said. "If
he can get his whole game together: overpowering fastball, great
stuff, great mound presence. Yeah, he's definitely one of those
guys who has the potential to be phenomenal in this league. The
ball explodes out of his hand."

Tim Redding matched Jimenez inning for inning in his third
strong start since rejoining the Mets' rotation Aug. 22. He
surrendered two earned runs on seven hits in 6 2-3 innings with
one walk and six strikeouts.

Seth Smith sent his 12th homer into the rock pile in
straightaway center to tie it at 1 in the first inning.

NOTES: Mets slugger Carlos Beltran, sidelined since June 22 with
a bone bruise on his right knee, began a minor league rehab
assignment Wednesday night for Class-A Brooklyn. He went 1-for-3
with a walk and an RBI as the DH. ... Newly acquired RHP Jose
Contreras threw a bullpen session Wednesday as he prepares for
his Rockies debut Saturday night against Arizona.