An Emiliano Buendia equaliser and a stunning Everton comeback against Crystal Palace meant it was a far from perfect evening for Burnley, despite still having survival in their own hands going into the final day.
A previously reliable Barnes began the match in the midst of a 15-month scoreless streak, and things could have been far worse when his elbow met the side of Tyrone Mings' head.
The Villa captain looked hurt as he hit the ground, but VAR wasn't used, much to the surprise of talkSPORT commentator and former Claret, Chris Iwelumo.
"It's a clear elbow to the face," he said. "If they are looking at it he's in big, big trouble."
Barnes managed to escape punishment though, which later proved crucial as he broke his barren goalscoring run from the spot after a calamitous Buendia took down Maxwell Cornet just before half-time.
The Argentine made amends soon after the break with a brilliantly taken equaliser from a John McGinn cross, but that was the only time Villa found the net.
Clarets goalkeeper Nick Pope then became the hero with a number of stunning saves, in particular a reaction effort with ten minutes to play, stopping a Bertrand Traore header that looked destined for the back of the net.
"What a save, and it's a brilliant header, fantastic," Iwelumo said. "Outstanding save from Nick Pope, so, so important."
But if Pope was the hero of the piece for Burnley fans, January signing Wout Weghorst was the villain, missing a guilt-edged chance with five minutes to play as Tyrone Mings flew in to block an open goal.
The Clarets were reduced to 10 men in stoppage-time when Matt Lowton picked up a well-deserved red due to a horror challenge straight after being subbed on, but Mike Jackson's side still held on.
Everton's 3-2 win over Palace after being 2-0 down confirmed their Premier League survival, meaning it's now just a two horse race between Burnley and Leeds.
However, with a far superior goal difference over Leeds, Burnley just need to match the Whites' score against Brentford in their final day clash with Newcastle to avoid relegation to The Championship.