Five grand slams were hit last night, the first time that has happened in 129 years of major league baseball.

Fernando Tatis of the St. Louis Cardinals and Jose Vidro of the Montreal Expos got it started early. Mike Lowell of the Florida Marlins connected, Bernie Williams of the New York Yankees followed and Jay Buhner of the Seattle Mariners set the record.

Buhner was unaware he had set the record.

"I did? That's cool. Right on!" he said.

Four grand slams had been hit in one day many times, most recently on July 28, 1998.

The five raised the major league season total to 96 -- the record of 141 was set in 1996.

After becoming the first player to hit two slams in the same inning on April 23 in Los Angeles, Tatis hit the third of his career off Billy Brewer in the fourth inning during a 12-6 win in Philadelphia. With three this year, Tatis tied Jim Bottomley (1925) and Keith Hernandez (1977) for the Cardinals' record.

Vidro connected on his first pitch from Carlos Almanzar in the sixth inning of the Expos' 8-0 win over visiting San Diego. It was his first grand slam and Montreal's first since last Aug. 27.

Lowell hit his first career grand slam on a 3-1 pitch in the eighth inning against San Francisco's John Johnstone, who had just relieved starter Livan Hernandez.

Williams's sixth career slam came at Oakland on a full-count pitch by reliever Mike Oquist, capping an eight-run second inning that gave the Yankees an 8-0 lead over the Athletics.

Buhner connected in the sixth inning at Safeco Field on a 3-1 pitch from John Snyder of the Chicago White Sox.