SAN FRANCISCO — Leo Durocher had lived enough baseball to know what the moment demanded: Sportsmanship, the personal acknowledgment of a job done well by a rival. Jackie Robinson had shown him the way.

Durocher had managed the New York Giants in 1951, when Bobby Thomson’s pennant-winning homer leveled the Brooklyn Dodgers. Even after such a bitter defeat, Robinson visited the Giants’ clubhouse to offer congratulations.

“I knew Jackie was bleeding inside,” Durocher wrote in “Nice Guys Finish Last,” his famous memoir. “I knew he’d rather have been congratulating anybody in the world but me. And still Jackie had come in smiling.”

Now it was 1962, on the West Coast, and again the Giants rallied in the ninth inning to stun the Dodgers for the pennant, taking the lead on a bases-loaded walk. Durocher, by then a Dodgers coach, wanted to do the classy thing.

“But I sat there without taking off my spikes, and I just couldn’t do it,” he wrote, listing the many Dodgers who had helped the team to 102 victories. “Seven key players having the best seasons of their career, and we couldn’t shake the Giants.”

One team is bound to feel those same emotions on Thursday night at 24 Willie Mays Plaza by the San Francisco Bay. The process of deciding a pennant is different now than it was in 1962, but these facts are identical: The Giants and the Dodgers were meeting with the same number of victories — more than 100 apiece, more than any other teams in the majors — and only one would survive.

In 1962, the teams were tied at 101-61 after 162 games, setting up a best-of-three playoff with a World Series berth at stake. This year, the teams are both seeking their 110th overall victory in the finale of a best-of-five National League division series.

Given the strength of both teams, it is a pity there is not more on the line than a date with the Atlanta Braves in the N.L. Championship Series. But this season was a true oddity, with the Dodgers matching their franchise high in victories with 106, but finishing second in the N.L. West a game behind the Giants, who set their franchise record with 107.

As a wild-card entrant to the playoffs, then, the Dodgers drew the fourth seed. They beat the St. Louis Cardinals last Wednesday to set up this clash with the Giants. The teams alternated outcomes for four games — Giants shutout, Dodgers rout, repeat — to land in a winner-take-all showdown, echoing the days of Durocher, Robinson and Mays.

“In any sport, when you’ve got generational rivals playing a meaningful series, and in this case, a very meaningful game, it just brings all that kind of talk back to life,” Dodgers Manager Dave Roberts said on Wednesday. “Those generational rivalries are kind of the foundation of this sport and what made it America’s pastime.”

Roberts would know: he played for both the Dodgers and the Giants, and his stolen base sparked the curse-breaking comeback for the Boston Red Sox over the Yankees in the 2004 American League Championship Series. Those rivals met in seven-game epics in both 2003 and 2004, but for all the star power on their rosters, they were not both 100-win teams.

The finale of this division series between Los Angeles and San Francisco is only the fifth time in baseball history that a pair of 100-win teams faced off in a winner-take-all postseason game. (The 1962 playoff was technically part of the regular season.) The Giants and the Dodgers are on the list, one long ago and one recently.

1912 World Series

This belongs on the short list of greatest games in baseball history. Christy Mathewson, who had famously spun three shutouts in the 1905 World Series, took a 2-1 lead into the bottom of the 10th at Fenway Park.

Giants center fielder Fred Snodgrass dropped a fly ball, then made a highlight-worthy catch (if highlights had existed then) to save an extra-base hit. But Mathewson walked the next hitter, then called off second baseman Fred Merkle on a foul ball that fell untouched. Given new life, Tris Speaker singled home the tying run, and Larry Gardner’s sacrifice fly won the title for Boston.

1931 World Series

The A’s were trying to become the first team to win three consecutive World Series, and they nearly did. They held Pepper Martin hitless — he’d gone 12 for 21 in the first six games — but Andy High and George Watkins both scored in the first and third.

The A’s couldn’t counter until they were one out away from elimination, when Doc Cramer singled home two against a tiring Burleigh Grimes. Bill Hallahan, who’d earned two complete-game victories, came on for the final out.

The Cardinals would continue to be fairly regular World Series participants, but the A’s would not return for 41 years. By then they were playing in Oakland, where they finally got that three-peat, winning the championship in 1972, 1973 and 1974.

1977 A.L.C.S.

It was bad enough that the Royals had lost the previous year’s best-of-five A.L.C.S. on Chris Chambliss’s home run off Mark Littell at a chaotic Yankee Stadium. This time, the Royals were home and took a 3-2 lead into the ninth inning as they sought their first pennant.

The Yankees didn’t let it happen, rallying for three runs off Dennis Leonard, Larry Gura and Littell, again. A single by Mickey Rivers drove in the tying run, and Willie Randolph’s sacrifice fly put the Yankees ahead. In the bottom of the ninth, Sparky Lyle — who had come in after five and a third shutout innings in relief by Mike Torrez — got a double-play grounder to end the game and send the Yankees to the World Series.

Reggie Jackson, who was benched by Billy Martin for this game, made that series his own with three home runs in the Game 6 clincher over the Dodgers.

2017 World Series

This was before the revelations of electronic sign stealing, which marred the Astros’ championship run. But it’s worth remembering that Houston clinched this World Series on the road, with no help from those noisy Minute Maid Park trash cans.

This game was all but decided before the sun went down over Los Angeles. George Springer lashed a leadoff double to left, scored on a throwing error in the Astros’ two-run first, then chased Dodgers starter Yu Darvish with a two-run homer in the second.

It was 5-0 Astros at that point, and while starter Lance McCullers Jr. didn’t last long either (he hit four batters), the Dodgers could not solve Charlie Morton. He closed out a 5-1 victory with four dominant innings, retiring Corey Seager on a ground out to Jose Altuve to end it.

Seager would have his moment for the Dodgers three years later, against Tampa Bay, when he hit .400 to win the Most Valuable Player Award in the World Series. The Dodgers had an impressive title defense this season but could not quite topple the Giants during the regular season — and Thursday will be their last chance.