Just last week, Lockman, speaking from his Scottsdale, Ariz., home told the New York Daily News about his ill health. On Thursday, his wife Linda told The News that his death was "very, very sudden."
Lockman spent the first 10 1/2 years of his career with the New York Giants, garnering MVP votes in '48, '49 and '52. But it was in 1951 that Lockman enjoyed his greatest moment between the lines, scoring the tying run on Bobby Thompson' "Shot Heard 'Round the World."
In August of that year Lockman and the Giants found themselves trailing their cross-town rivals, the Brooklyn Dodgers, by 13 1/2 games in the standings. Over the next two months, the Giants went a staggering 37-7 to tie the Dodgers for first place in the National League.
During the rubber match of a three-game playoff to determine who would serve as cannon fodder for the Yankees in that year's World Series, the Giants found themselves trailing 4-1 in the bottom of the 9th inning.
Lockman eventually came to the plate with men on the corners and one out. His double cut the Dodgers lead to 4-2 and drove starter Don Newcombe from the game.
Ralph Branca, the losing pitcher for the Dodgers in Game 1, was called upon to face Bobby Thompson, who promptly launched a 3-run homer into the leftfield seats, capping one of the greatest comebacks of all time and sending the Giants to the Series.
The headline on The New York Daily News' recap the following day read "The Shot Heard 'Round the Baseball World." The word "Baseball" was quickly dropped by those discussing the historic homer.
The opening of Don DeLillo's1997 novel "Underworld" finds Jackie Gleason, Frank Sinatra, J. Edgar Hoover and legendary barkeep Toots Schorr enjoying the game from the comfort of Dodger manager Leo Durocher's seats.
This section was later published separately as a novella under the title "Pafko at the Wall," a reference to Dodger leftfielder Andy Pafko, who could only look up and watch helplessly as Thompson's shot headed for the seats.
Though the Giants went on to lose the World Series to the Yankees, the core of that team, including Lockman, would return to the Fall Classic in 1954 and sweep the Cleveland Indians.
During his 15-year career, Lockman batted .279 with 114 home runs and 563 RBI, and made one All Star team.
"He died with a lot of dignity, and we're gonna get through this," Linda Lockman told The News. "We just miss him so much."