SAN FRANCISCO (AP) _ Shawn Estes collided with second base so hard, his left foot buckled under the pressure.

Estes, the San Francisco Giants' starter in Game 2 Thursday night, walked to lead off the third inning with the New York Mets ahead 2-1.

One out later, Bill Mueller grounded the ball into the hole between shortstop Mike Bordick and third baseman Robin Ventura. Bordick tried to force him out at second and Estes _ who didn't attempt to slide _ jammed his ankle into the bag.

Estes jumped off the base in pain, limping toward the Giants dugout, then fell and was tagged out. Giants trainer Stan Conte ran to his side, and helped him off the field along with another trainer.

X-rays were negative, and the Giants reported that Estes had a sprained left ankle.

``He's disappointed he couldn't keep going on,'' Conte said after the game. ``He was anxious about the injury, but glad the X-rays were negative.''

Conte said Estes would likely leave the ballpark on crutches, but was still going to make the trip to New York for the next two games in the best-of-five playoff series.

The Mets beat the Giants 5-4 Thursday night, evening the series at 1-all.

``I think he's more down than anything,'' shortstop Rich Aurilia said. ``You don't want to come out of a game like that.''

Estes, a left-hander who went 15-6 in the regular season, was replaced by Kirk Rueter, another lefty who was 11-9 for the Giants.

Rueter was able to keep the Mets scoreless for 4 1-3 innings, allowing just three hits. He walked one and struck out one.

Estes, making his second career postseason appearance, lasted three innings, allowing two runs, three hits and three walks with three strikeouts. Timo Perez hit a two-run single off Estes in the second inning, giving the Mets the early lead.

Giants manager Dusty Baker had not announced whether Estes would go again against the Mets, and it was too soon to tell when Estes might be available next.

``I know if there's any way he can get back in it, he will,'' Aurilia said.