According to the Baseball Almanac, a Super Walk-off Grand Slam is when a player on the home team hits a bases loaded home run when trailing by three runs in the bottom of the ninth inning to win the game. It's not as common as you think, and surprisingly, accomplished by many players you'd never suspect. Travis Hafner of Cleveland might be an exception -- he did it against the Blue Jays last night, July 7th, 2011.
"Hafner said he got a tip from teammate Michael Brantley, who struck out against (Blue Jays Reliever Luis) Perez. Brantley told Hafner that Perez's fastball had some sink to it, so Hafner looked for something up in the zone that he could drive. "It's awesome. There's nothing like it," Hafner said of his walk-off slam. "It's the most fun you can have on the baseball field. It's great."Link:
http://mlb.mlb.com/mlb/gameday/index.jsp?gid=2011_07_07_tormlb_clemlb_1&mode=recap_home&c_id=cleAmerican League Super Walk-off Grand Slams: Babe Ruth, 09-24-1925 / New York Yankees
Eddie Joost, 07-15-1952 / Philadelphia Athletics
Ron Lolich 04-22-1973 / Cleveland Indians
Buddy Bell, 08-31-1984 / Texas Rangers
Phil Bradley, 04-13-1985 / Seattle Mariners
Dick Schofield, 08-29-1986 / California Angels
Alan Trammell, 06-21-1988 / Detroit Tigers
Chris Hoiles, 05-17-1996 / Baltimore Orioles
Jason Giambi, 05-17-2002 / New York Yankees
Travis Hafner, 07-07-2011 / Cleveland Indians
National League Super Walk-off Grand Slams: Roger Connor, 09-09-1881 / Troy Trojans
Sammy Byrd, 05-23-1936 / Cincinnati Reds
Jack Phillips, 07-08-1950 / Pittsburgh Pirates
Bobby Thomson, 06-16-1952 / New York Giants
Del Crandall, 09-11-1955 / Milwaukee Braves
Danny Kravitz, 05-11-1956 / Pittsburgh Pirates
Roberto Clemente, 07-25-1956 / Pittsburgh Pirates
Ellis Burton, 08-31-1963 / Chicago Cubs
Tony Taylor, 08-02-1970 / Philadelphia Phillies
Carl Taylor, 08-11-1970 / St. Louis Cardinals
Roger Freed, 05-01-1979 / St. Louis Cardinals
Bo Diaz, 04-13-1983 / Philadelphia Phillies
Brian Giles, 07-28-2001 / Pittsburgh Pirates
Adam Dunn, 06-30-2006 / Cincinnati Reds
Brooks Conrad, 05-20-2010 / Atlanta Braves
Source:
http://www.baseball-almanac.com/feats/walk_off_grand_slams.shtml