But Huddersfield, on the back of four successive victories, refused to give up and levelled deep into stoppage time through Wells.
Huddersfield dominated the first half and, with Blackburn notorious slow starters, almost took the lead inside the first minute.
Rovers goalkeeper Jason Steele pulled off a great double save, blocking Rajiv van La Parra’s effort before turning away a well-executed overhead kick from Kasey Palmer.
Centre-back Michael Hefele’s header was well wide from Aaron Mooy’s driven cross and van La Parra whipped a ball in for Wells but his flick header lacked power and was easy for Steele.
A fast attacking move by the home side, which involved good work by Elias Kachunga, deserved a better finish than a snatched shot over the top from Wells.
Wells turned provider with a lovely through ball for Kachunga but his shot was straight at Steele.
The keeper was there again just past the half hour when Hefele slipped a pass inside the full-back and Kachunga delivered from the right for Wells but Steele spread himself to make the block.
Rovers had just one chance in the first half when Sam Gallagher broke away and ran at the Town defence.
The defenders backed off and Gallagher squared for Graham sliding in but the striker was inches away.
Huddersfield did not dominate the second half as much, with Rovers making them battle all the way.
The home side brought on Harry Bunn and Jack Payne for van La Parra and Palmer in a bid to break down Blackburn’s stubborn resistance.
There were fewer chances and too often the final pass was lacking for the home side.
Chris Lowe’s free-kick was straight at Steele and while Wells caused problems, beating two defenders, the move ended with Lowe’s cross dropping just short of Bunn.
Tommy Smith dragged a shot wide and Wells again could not put Bunn away when clear in front of goal.
Against the run of play Rovers snatched a goal when Liam Feeney was sent clear on the right and crossed deep for Graham to head home at the far post in the 81st minute.
Huddersfield refused to give up, however, and equalised after Elliott Bennett fouled Payne on the edge of the box.
From a central position Wells bent the ball around the wall leaving Steele no chance.