of the Toronto Blue Jays on July 30. Norris surrendered both in the same week, and it was the second game-winning walk-off grand slam by Pearce in the same week. A walk-off grand slam that erases a three-run deficit is also called an ultimate grand slam. There have been 32 such instances documented in major league history – all taking place during the regular season, 16 of those coming with two outs. Of the 32 home runs, only Roberto Clemente's was hit inside the park, at spacious Forbes Field on July 25, 1956. Pirates manager/third base coach Bobby Bragan instructed him to stop at third, but Clemente ran through the stop sign to score the winning run. Alan Trammell's June 21, 1988 and Chris Hoiles' May 17, 1996 grand slams occurred under the most dire situation: bases loaded, two outs, full count, bottom of the ninth inning, and down by three runs. Donaldson's and Stanton's aforementioned walk-off grand slams are each the two most recent occurrences of an ultimate grand slam. Walk-off celebration injury Walk-off celebrations typically consist of an entire baseball team leaving the dugout to meet a player at home plate after the batter hits a walk-off home run, or at whichever base the hitter happens to reach if a traditional base hit results in a walk-off victory. Players often encircle teammates who hit a walk-off before dancing and roughhousing to celebrate their victory. During a walk-off celebration on May 29, 2010, Kendrys Morales, then a member of the Los Angeles Angels of Anaheim, broke his left leg while celebrating a walk-off grand slam. As a result of this injury, team manager Mike Scioscia instituted new guidelines for his team that ensured a much tamer response to all subsequent walk-off victories. Relevant rules The rules of baseball provide that: A batter is entitled to a home run only "when he shall have touched all bases legally." (Rule 6.09(d); also 7.05(a)) A batter is out, on appeal, for failing to touch each base in order or for passing a preceding runner. In some cases, all runs that score are negated. (Rule 7.10 and 7.12) On a game-winning hit, a batter is credited for the full number of bases only if "the batter runs out his hit." (Rule 10.06(f)) A game-winning home run is allowed to complete before the game ends, even if it puts the home team ahead by