Joe Cronin died yesterday at his Cape Cod home in Osterville, Mass., 51 years after winning Washington's last American League pennant as the fiery shortstop of the Senators and youngest playing manager known to the major leagues. He was 77. He had cancer.

He was the other San Francisco kid, from the city's poor section, who beat Joe DiMaggio into the big leagues, as a regular, by seven years and went on to his own storied fame as an achiever in the 20 years spent in the grime of the playing field. For 15 years after that, he was the president of the American League.

He made it, at various points, as the American League's most valuable player (1930); as pennant-winning manager, league's best shortstop, league-leader in doubles and shortstop on the first American League all-star team (all in 1933); as winner of another pennant (with the Red Sox) in 1946; with election to the Hall of Fame (1956), and as league president (1959-73).

He was, in 1934, the center of baseball's most stunning deal. One year after his Senators won the pennant, Clark Griffith sold his manager to the Red Sox for the $250,000 in cash offered by Tom Yawkey. The deal by far eclipsed all previous player transactions.

Griffith was then Cronin's father-in-law and uncle by the player's marriage to Mildred Robertson, niece, adopted daughter and secretary of the team's owner. Griffith rationalized the deal by saying flatly, "No player is worth $250,000." He also was influenced by the Senators' seventh-place finish that season.

Cronin joined the Senators in 1928. From 1929 to 1934, Washington fans were blessed with, arguably, the league's best shortstop. Nobody could go as deep in the hole for a ground ball as Cronin, with his rifle arm. Knowing its power, he'd decreed, as manager, that he would take all relays possible from the outfield.

On the field, Cronin was giving Washington fans a show. His jutting jaw was thrust at malfeasant umpires at every excuse.

In the second year of the all-star game, Cronin was named manager of the AL team. "What a lineup," he once recalled. "I had Babe Ruth, Lou Gehrig, Jimmy Foxx, Al Simmons, Bill Dickey and Charley Gehringer and Lefty Gomez in my lineup. What a dream team."

That day, Cronin was one of the five successive baseball greats who were struck out by Carl Hubbell in his famous feat of the 1934 all-star game at the Polo Grounds. In order, he struck out Ruth, Gehrig, Foxx, Simmons and Cronin. "But I was the star of that group," Cronin said. "I got a foul off Hub."

In 1925, scout Joe Devine signed him off the San Francisco sandlots for the Pittsburgh Pirates. In 1926-27, he got into 50 games for the Pirates but was shipped to the minors with no strings attached, indicating he didn't impress anybody.

In 1928, Washington scout Joe Engel was foraging in the Midwest with orders from Griffith to find a shortstop. He spotted Cronin playing for Kansas City. "I paid $7,500 for him," Engel said, "when I knew I had no authority from Griffith to spend that much."

When Griffith was advised of the purchase, the old gentleman was furious. "Seventy-five hundred for a kid shortstop who is hitting .245 in the minors. Are you crazy?" he told Engel over the phone.

When they came to Washington, Engel took Cronin into the Griffith Stadium office but bade him wait downstairs until he could get more intelligence as to Griffith's current frame of mind. Meanwhile, he introduced the rookie to Robertson in the outer office. "Hi ya, Millie," he said to Griffith's niece-adopted daughter-secretary. "Been scouting for a husband for you and just brought him in from Kansas City. Meet Joe Cronin." A prophecy.

Griffith saw a skinny, gangling kid with awkward arms and elbows who had the schoolboy habit of dipping one knee toward a ground ball. At bat, Cronin was just as unorthodox, facing the pitcher with a square stance that showed no sign of power in his stroke. Griffith glared at Engel.

On the road, Manager Bucky Harris worked Cronin into the lineup, enraging Griffith, whose favorite was Bobby Reeves. "Reeves will never be a shortstop if you don't play him," Griffith wired Harris, who wired back, "Neither will Cronin." Harris prevailed, and in 1929 Cronin was a rising star, hitting .281 and making all the plays.

The next year, it was Cronin hitting a thumping .346. He was also hitting the ball to right field, with power, and had become a problem for all the league's outfielders, this right-handed hitter who could pull, push or hit straight away. He had arrived. He would bat .301 for his 20-year career.

Came 1933, and Griffith needed a new manager to succeed Walter Johnson, the pitching hero, who couldn't inspire the team as manager. Griffith had always chosen a manager from the ranks since 1920 and speculation was that he would select either the veteran Joe Judge or Sam Rice. Surprise! He tapped Cronin.

And they won the pennant that year, beating the Yankees by seven games. Cronin's contribution was a .309 average, the best shortstopping in the AL, and judicious use of his pitchers.

Washington whooped it up in a Pennsylvania Avenue parade. It was highlighted by the trucks from the Cherrydale, Va., fire department, with the words emblazoned on streamers, "Let Cherrydale Burn."

Alas, they lost the World Series to the Giants in five games, twice licked by the villainous, screwballing Hubbell.

One day in high excitement after joining the Red Sox, Cronin advised Griffith of "the best-looking young hitter anybody ever saw . . . His name is Williams. Wait until you see this one next spring. You won't believe how he hits."

It was Ted Williams, of course. Immediately, the Red Sox fortunes took a better turn. Four second-place finishes under player-manager Cronin, and then, in 1946, the first Red Sox pennant since 1918.

Last May, Cronin returned to Fenway Park to watch, from a wheelchair, the ceremonies retiring for all time the only two uniform numbers ever memorialized by the grateful Red Sox. They were No. 4 (his) and No. 9 (Williams'). In Fenway Park, Joe Cronin was hearing the cheers once more.