Complex sentence: Box Hill entered the Victorian Division 4 in 1925 and went through the season, losing one game and drawing one game, as they became champions and won promotion to division 3 for the 1926 season.
Split into simpler sentences: Box Hill entered the Victorian Division 4 in 1925. In their first season they lost one game and drew once to became champion and win promotion to division 3 for the 1926 season.