Richard Stearman thundered in a second-half header as Sheffield United cranked up the pressure on leading pair Norwich and Leeds.
Boro were reduced to ten men, with their top-six place under threat.
Daniel Ayala was sent off for a second yellow card shortly after Blades substitute Stearman converted Oliver Norwood's wicked free-kick.
There was little between the sides from start to finish but United's sense of adventure, with three strikers on for the second half, gained its reward in the end.
For both teams it was a test of resilience, having been rocked by late goals in their previous games.
Incredibly, Boro conceded in the 101st minute for a 1-1 home draw with Leeds following a long delay over Jack Clarke's collapse on the visitors bench.
But it was even more remarkable that Sheffield United had to share the spoils at Villa Park last Friday after leading 3-0 with eight minutes to go.
That turnaround left the Blades trailing Norwich and Leeds at the top of the Championship while Boro, who could have advanced their own automatic promotion ambitions, were far from secure in the play-offs.
In fact, neither side had a truly comfortable cushion on a top six place as they met for the first time since August 7th.
Pulis's side won 3-0 at the Riverside as Wilder's men began the campaign on a wobble.
Now both look strong for the final straight. Boro arrived on the back of a six match unbeaten run in the league while United were showing just one defeat in nine, having won their last four at home.
In Billy Sharp, they had the hottest marksman in the country - 23 goals for the season and, after a hat-trick at Villa, 11 in his last nine games.
But injury and suspension had stripped Wilder of both his famed overlapping centre backs, Jack O'Connell and Chris Basham, to give the line-up an unfamiliar look.
The Blades boss refused to sacrifice his attacking system, drafting Martin Cranie and Enda Stevens into the key roles, as the home team started on top.
Mark Duffy had a deflected 20-yard shot turned round a post by Darren Randolph.
Boro entrenched themselves despite an injury forcing off Aden Flint and Jordan Hugill failed with a chance on the break.
The striker was then unlucky with a 20-yard floater brilliantly saved by Dean Henderson.
A frantic start to the second half was in total contrast to the first. George Friend had a header cleared from the United line by John Egan following Ryan Shotton's long throw.
Then substitute Stewart Downing fired in a shot saved at the second attempt by Henderson.
Blades sub Gary Madine, on for Duffy, was at the centre of a loud penalty appeal, looking to have been pulled back.
Sharp had an effort disallowed for offside but United's pressure told.
Oliver Norwood delivered a superb inswinging free-kick and Richard Stearman, who replaced Baldock in the first half, thumped home a header.
Boro were further rocked by a second yellow card in quick succession for Daniel Ayala, reducing his side to ten men.