Goals from summer signings Uche Ikpeazu and Matt Crooks, in the 38th and 70th minutes respectively, sealed three points for Boro.
That was the perfect outcome for Warnock – despite City levelling through Andy King’s header on the hour – who had waited more than a year to lead Middlesbrough in front of a big Riverside crowd.
Warnock celebrated at the final whistle with the supporters who regularly chanted his name and the 72-year-old admitted he did not realise how special the atmosphere was going to be.
“I was gobsmacked before kick-off when I came out, it was an amazing sight, that is why I am in the game,” said Warnock, who took over during the pandemic in June last year. “I have been here I don’t know how many months, and that’s what I have been waiting for. I thought at 1-1 they were brilliant. We had a 10-minute sticky spell. All credit to them for helping us through.
“It was great to score two in your first home match in front of the fans. I went to clap them after the game, they were all over the shop. It was fabulous.
“A big ‘thank you’ to them from us. Everywhere deserved a clap, they contributed all over the ground. (It was) great to see so many young fans inside too.
“And the two new signings getting on the sheet, fabulous. Crooks has so much energy, (I’m) delighted for him.”
Middlesbrough: Lumley, Anfernee, Dijksteel, Hall, Fry, Bola, Crooks, Howson, McNair, Spence, Ikpeazu (Payero 72), Jones (Bamba 90). Unused substitutes: Daniels, Morsy, Peltier, Sivi, Coburn.
Bristol City: Bentley, Vyner (Kalas 79), Baker, Atkinson, Dasilva, James, King, Weimann, Scott (Janneh 74), Palmer (Wells 58), Martin. Unused substitutes: Simpson, O’Leary, Bakinson, Massengo.
Referee: O Langford (W Midlands).