The automatic promotion contenders contested a 1-1 draw at the Keepmoat Stadium but the hosts will feel they should have clinched a first win in five games after dominating for long periods.
A blunder by Rovers goalkeeper Gary Woods gifted the Glovers the lead in the sixth minute when he fumbled a free-kick from Jamie McAllister and Paddy Madden popped up to slam home his 19th goal of the season - and his 11th in the last eight games.
Billy Paynter grabbed a deserved equaliser for Doncaster on the stroke of half-time.
"We got the goal early and we always knew Doncaster would come back at us," said Johnson.
"When you get used to winning like we have you are always disappointed when the run comes to an end. But we can't be too unhappy that we've come to one of our main promotion rivals and gone away with a point.
"It wasn't a classic game of football but, in a sense, it was a match between two teams that couldn't afford to lose.
"The pitch didn't help matters because both teams normally like to play football, but we showed we can adapt and we produced the workrate required not to get beat when they came at us in the second half."
On Madden's recent form, Johnson added: "He's in an unbelievably rich vein of form. I only wish the goal had been enough to win the game but, in fairness, it was pretty even overall."