In the 2001–02 season, Horsfield was chosen Player of the Year both by Birmingham's fans and by his teammates. His strike partnership with Stern John proved crucial in the unbeaten run which helped Birmingham reach the First Division play-offs, and he scored the equaliser against Norwich City in the play-off final, which the club went on to win on penalties to earn promotion to the Premier League. Horsfield had promised a donation to his first club, Athersley Rec, if he ever reached the Premiership; a few days after the play-off victory he gave them £25,000 towards improving their facilities.