Throughout these growing years, the Western Mustangs joined the senior intercollegiate ranks as changing coaches, players, rules, and rivalries pushed the team to new heights and new facilities. Basketball was Western's leading sport in the number of participants with plenty of teams available for men and women at all levels.
In the 1923-24 season, Western won its first intermediate intercollegiate title and the right to play at the senior intercollegiate level. According to the Occidentalia yearbook, the most noteworthy observation of the season was not the championship, but rather that “contrary to the psychological laws governing the prowess of athletes, the team did not play as well in the home games as they did in the out-of-town games.”
Regardless, the winning season generated optimism for a strong show on the senior intercollegiate stage alongside McGill, Toronto, and Queen’s. In its first senior game against Toronto, the Mustangs lost 27-17. The Mustangs charged back in their game against defending champions, the Queen’s Gaels. For the first time in three years, the Gaels lost and Western celebrated with an impromptu parade down London’s Dundas Street. Despite the advent of intercollegiate play, Arts and Meds basketball remained popular with over one hundred players registered.
Under the direction of Coach Jack Lang, the 1926-27 Mustangs won four of six league games, and the first senior intercollegiate title for Western in any sport.
The speed of the game increased in 1937 when the basketball rules changed; instead of returning to center for a jump ball after every basket, the new rules stated the ball would be put in play at the end line. The change only helped the Mustangs as the team, captained by Jim Farmer, went undefeated in season play and won the championship.
The next season, the Mustangs finished in a three-way tie for first place with McGill and Toronto, and a two-way tie in the 1939-40 season with Toronto.
The basketball facilities had already moved from the local YMCA to the London Armouries in 1913, and even after the move to the London Beal Tech high school gym, the space could not accommodate athletics and the compulsory undergraduate physical education classes.
All these space and sport considerations were suspended for the duration of the Second World War, from the 1940-41 through to the 1944-45 season.