Crewe Alexandra manager Steve Davis hailed match-winner Ryan Colclough after his last-minute goal at Bramall Lane.Play-Off hopefuls Sheffield United appeared to have claimed at least a point when Jason Holt, on loan from Hearts, cancelled out Lauri Della Valle's first-half opener.
But Crewe substitute Colclough, who has been absent for 16 months due to injury, propelled the visitors to their first ever win at Bramall Lane.
"That goes to show what Ryan can do," Davis said. "He's been out for so long, but now he's shown that he's back.
"It was an exceptional strike. It showed our intent at that stage because it would have been easy to shut-up shop.
"I could have told Ryan to take the ball into the corner, but I don't think he would have listened anyway!
"Instead, he cut inside and it hit the back of the net faster than it left his foot."
Crewe are fighting for survival at the opposite end of the table to the Blades, and moved out of Sky Bet League 1's bottom four with the three points.
Davis added: "It was a great win for us because it was an expected win.
"I think you'd have got pretty long odds on that before the game.
"It's difficult because of the teams that are in it and the teams that are going to be coming down for us.
"But moments like this make you realise why you are in football. You get lots of downers, but this was a massive lift."