Warnock made four second-half changes in a bid to force a winner and it paid off as Saville poked home from close range in the 87th minute - just two minutes after coming on - to secure a 2-1 win at St Andrew’s.
Boro trailed early on after Anfernee Dijksteel turned Michael Rose’s flick-on into his own net following a long throw but Grant Hall headed home a pinpoint free-kick from Paddy McNair to bring the visitors level.
Warnock said: “I thought all the subs did well tonight. It’s nice to have a bench that you can turn to and try to change a game, and we’ve got that at the moment. I’m delighted because they all contributed.
“After another long throw disaster - that’s two in two games - I thought we grew into the game and I think we deserved it in the end.
“It was a world-class free-kick for the first goal and then in the second half I always felt we had the edge and we just couldn’t get that goal but it paid off in the end.
“We’re only three points off top six - it is a good platform. The lads have thrown so many points away, it is frustrating. We could quite easily have nine or 10 more points and be looking at a different ball game.
“We’ve got some tough games coming up but everybody has, in this league you can’t predict anything.”
Coventry, meanwhile, paid the price for failing to register a single shot on target as they remain six points above the bottom three in 20th but boss Mark Robins could not fault their effort.
He said: “We had dealt with everything really - they had not really created a great deal other than the brilliant ball in from Paddy McNair for the equaliser. Before that, there was nothing from them.
“The changes they made, there’s Premier League quality there. But we still looked like we were the ones who were going to go on and get the win.
“There were chances that we had, the quality was just lacking from time to time and unfortunately we’ve succumbed to the pressure they were able to build and that’s the disappointment.
“With the quality and experience they have, it can tell - and we let it tell. That’s the only disappointment for us. We’ve had enough of the ball to create something better to get another goal.
“We’ve got 12 games left - we’ve got to pick some points up but so has everybody else. We’re a decent team - if we continue in the same vein, we will pick results up.”
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