In 1904, MacLaren led Lancashire to victory in the County Championship, their only such success under his captaincy. Unusually for a Championship-winning team, the club relied heavily on batting rather than bowling. MacLaren played several big innings, scoring at a rapid pace, as his team began the season with a string of victories. Their form faded later in the season, but they remained unbeaten. In all first-class cricket, MacLaren scored 1,191 runs at 31.34. At some point during the season, he was asked by Ranjitsinhji, a close friend, to become his private secretary, and both men travelled to India during the winter of 1904–05. Ranjitsinhji at the time was pursuing his claim to the throne of Nawanagar, and he remained in India when MacLaren returned to England for the 1905 cricket season.