SAN JUAN, Puerto Rico (Ticker) -- Cliff Floyd 's pain was Eric Valent 's gain.

Valent replaced an injured Floyd and hit his first major league homer as the New York Mets defeated the Montreal Expos , 4-1, in the rubber game of their three-game series.

Of greater concern for the Mets is the health of Floyd, one of their most productive hitters who suffered a strained right quadriceps while running to first base on an infield single in the first inning. Floyd immediately grabbed his right thigh and needed assistance to leave the field.

Floyd, whose 2003 season was cut short by an Achilles injury that required surgery, will be re-evaluated Monday when the team returns to New York.

"I think it's a really bad strain," said Floyd. "I felt it stretch, but there was no pop."

"We'll have an MRI done first thing in the morning," Mets manager Art Howe said. "We'll know more about his situation, but it doesn't look like he'll be able to play for a while."

Valent, who was selected by the Mets from Cincinnati in the Rule 5 minor league draft in December, replaced Floyd in the lineup and delivered in the sixth, belting a two-run homer off Livan Hernandez (0-1) to give the Mets a 3-1 lead.

"I just wanted to get the run in," Valent said. "I saw that big curve ball that I recognized early. He throws that big slow curve ball and I recognized it."

It was more than enough for Tom Glavine (2-0), who allowed an unearned run and five hits over seven innings. David Weathers and Mike Stanton followed before Braden Looper worked the ninth for his first save as a Met.

The Mets also were forced to hold their breath when Mike Piazza , who has 350 career homers as a catcher - one shy of Carlton Fisk 's major league record - made his first start of the season at first base.

Piazza did not make an error, but was knocked down by Montreal's Peter Bergeron while reaching for a throw off the bag. Piazza appeared to be shaken up, but remained in the game.

Hernandez (0-1) allowed three runs and seven hits in seven innings.

Glavine started the Mets' rally in the sixth with a single and went to third on a double by Kaz Matsui. Todd Zeile hit a sacrifice fly before Valent homered to right field.

"When you can't get the pitcher out it gets you in trouble," Expos manager Frank Robinson said.

Ty Wigginton made it 4-1 with an RBI single in the ninth for the Mets, who won two of three games in Puerto Rico after being swept in a four-game series here last April.

Montreal has scored just 10 runs in its first six games.

"We have to find a way to get the offense going," second baseman Jose Vidro said. ""We've played six games and haven't passed 10 yet."

The Expos scored their only run in the third when Bergeron reached on a bunt single and went to second when Glavine threw the ball away. Bergeron moved to third on a groundout and scored on a sacrifice fly by Vidro.