A 71st-minute winner from substitute Danny Ward ended the Millers’ seven-match winless streak as they moved to within three points of safety, with a late loss for fourth-from-bottom MK Dons against Blackburn Rovers adding gloss to a good day all around for the hosts.
That said, controversy reigned at the interval after referee Mark Brown awarded the visitors a hugely debatable penalty just before the break after Sergio Canos theatrically when down after a clean challenge from Lee Frecklington won the ball - with Alan Judge netting the rebound after Lee Camp blocked his spot-kick.
That cancelled out Matt Derbyshire’s 29th-minute winner, but Ward ensured the day belonged to the Millers and Warnock, who claimed the first win of his tenure in charge at the fourth attempt.
Warnock said: “The players gave me absolutely everything. That’s the Championship and they have to give that as a minimum. I really, really enjoyed it.
“We had to overcome half-time when they were all flat with the penalty decision and it is difficult when you concede a goal like that when you know it is an injustice.
“Their manager even said it wasn’t a penalty and Judgey (Alan Judge) was laughing at me at the bench. I said to him: ‘Wait while ninety minutes is up, son.’ Thank goodness...
“I said to the lads: ‘We have got to forget about that (penalty award) now, we’ve got another 45 minutes and take the win, it can’t all go against us.’
“The fans were fantastic and Wardy came on and took his goal really well and could have had a hat-trick while he was on.”
Bees boss Dean Smith admitted that his side’s penalty was a very harsh award, which he felt was the wrong call on watching a re-run of the incident.
And he admitted to feeling frustration himself with the officials with the way in which the second-half was officiated.
He said: “In the second half of the game, we got involved in a tear-up and that’s not our game. Our game is playing football and passing and moving it.
“We gave the opportunity to the officials to give too many free-kicks away for us.
“I thought we had a very harsh penalty, I think their lad touched the ball.
“At the time, I thought it was a penalty, but seeing it back, their lad touched the ball and I can understand their frustration.
“But my frustration was that I don’t think the second half was managed or officiated in the same way as the first-half.
“The penalty decision made it a bit of a cauldron of hate towards the officials. It got Rotherham supporters’ tails up.”
Rotherham United: Camp; Richardson, Broadfoot, Wood, Mattock; Halford, Frecklington (Green 81), Smallwood, Thomas (G Ward 76); Derbyshire, Best (D Ward 64). Substitutes unused: Kenny, Kelly, Newell, Clarke-Harris.
Brentford: Button; Yennaris, Dean, O’Connell, Bidwell; Swift, McEachran (Kerschbaumber 78), Woods; Canos (Vibe 83), Judge, Djuricin (Hofmann 64). Substitutes unused: Saunders, Clarke, Bonham, Barbet.
Referee: Mark Brown (East Yorkshire).
Attendance: 8,534 (556 Brentford supporters).