Boss John Gorman had reverted to playing three strikers from the start in a ploy to guarantee the wins necessary to pull off a possible play-off challenge.
Dixon, who enjoyed a spell on loan at Conference side Aldershot earlier in the season, was brought on for midfielder Gus Uhlenbeek with six minutes remaining.
"I’m very disappointed because 99% of the work was done and I couldn’t finish it off," said Dixon.
Although the Chairboys left Blundell Park disappointed after only managing a draw, elsewhere results last weekend went in their favour and the Bucks side remain within three points of the final League Two play-off position with four games remaining.