Pivotal World Series Moments
Ruth Homers Twice
1923 World Series Game 2: New York Yankees @ New York Giants
After losing Game 1 5-4 on Casey Stengel's 9th inning inside-the-park homer at Yankee Stadium, the American Leaguers needed a victory at the Polo Grounds to even the series.
Right-hander Hugh McQuillan (15-14) started for the Giants while the Yankees count­ered with southpaw Herb Pennock (19-6 for an American League leading .760 winning percentage).
Pennock was the 11th player that the Yankees obtained from "the always-generous" Red Sox since Boston owner Harry Frazee needed to raise money to fund his Broadway musicals and burlesque in 1919. The 11-year veteran was coming off a 17-loss season for Boston, but pitching at cavernous Yankee Stadium, the control specialist blossomed.
The Yanks jumped in front in the second inning on 2B Aaron Ward's towering solo home run into the left field upper deck, but the Giants immediately tied the score in the bottom of the inning when LF Irish Meusel clouted a homer just as high into the same area.

L: Herb Pennock; R: Babe Ruth follows his home run in Game 2.
Ruth's Back-to-Back Homers Put Yanks Ahead for Good
When Babe Ruth led off the fourth, McQuillan tried the same slow ball strategy that frustrated Babe so badly the year before. The New York Times writer described what happened this way:
This time Ruth lunged with all his force, and with the crack of the bat there was no doubt where the ball was going. It started on such a high arc that (RF Ross) Youngs was deceived and rushed over to the edge of the stand to make the catch. There he stood and looked up to see a baseball going faster than it had ever gone before, going up and up until it disappeared from sight beyond the roof of the big stand.
The Yanks added another run in the fourth on singles by 1B Wally Pipp, C Wally Schang, and SS Everett Scott. Lefty Jack Bentley replaced McQuillan and ended the inning without further damage.
The score remained 3-1 when Ruth came to bat again with one out and no one on in the fifth. This time he took advantage of the Polo Grounds' friendly right field dimension (259'). As the New York Times writer put it, "The second of the historic drives was only a glorified fly that became a home run by the grace of a short right field stand." Three other men had hit two homers in a World Series game, but Babe was the first to do so in successive at bats.

L-R: Wally Pipp, Wally Schang, Jack Bentley, Polo Grounds dimensions
The Giants got a run back in the sixth on three straight singles by 3B Heinie Groh, 2B Frankie Frisch, and RF Ross Youngs. But Pennock bore down and got a forceout and a double play to avoid further damage. 4-2 Yankees
Neither team scored again, and Pennock finished with a nine-hitter with only one walk to even the Series at a game apiece.
References
Game Day Yankees Baseball: The Greatest Games, Players, Managers and Teams in the Glorious Tradition of Yankees Baseball (2006)