When the American League Browns moved from Milwaukee in 1902, they built a new version of Sportsman's Park. They initially placed the diamond and the main stand at the northwest corner of the block.
This Sportsman's Park saw football history made. It became both the practice field and home field for Saint Louis University football teams, coached by the visionary Eddie Cochems, father of the forward pass. Although the first legal forward pass was thrown by Saint Louis's Bradbury Robinson in a road game at Carroll College in September 1906, Sportsman's Park was the scene of memorable displays of what Cochems called his "air attack" that season. These included a 39–0 thrashing of Iowa before a crowd of 12,000 and a 34–2 trouncing of Kansas witnessed by some 7,000. Robinson launched an amazingly long pass in the game against the Jayhawks, which was variously reported to have traveled 48, 67 or 87 yards in the air. College Football Hall of Fame coach David M. Nelson called the pass extraordinary, "considering the size, shape and weight" of the fat, rugby-style ball used at that time. Sports historian John Sayle Watterson agreed. In his book, College Football: History, Spectacle, Controversy, Watterson described Robinson's long pass as "truly a breathtaking achievement". St. Louis finished with an 11–0 record in 1906, outscoring its opponents 407–11.
In 1909, the Browns moved the diamond to its final location, at the southwest corner, in the shadow of a new steel and concrete grandstand—the third such stadium in the major leagues, and the second in the American League (after Shibe Park). The previous wooden grandstand was retained as left-field bleachers for a while, but was soon replaced with permanent bleachers. The Cardinals came back to their original home in mid-1920, as tenants of the Browns, after abandoning the outdated, mostly-wooden Robison Field.
After nearly winning the American League Pennant in 1922, Browns owner Phil Ball confidently predicted that there would be a World Series in Sportsman's Park by 1926. In anticipation, he increased the capacity of his ballpark from 18,000 to 30,000. There was a World Series in Sportsman's Park in 1926—but it was the Cardinals, not the Browns, who took part in it, upsetting the Yankees in a memorable seventh game.