BARNSLEY let a two goal lead slip away as they lost 3-2 at home to Mansfield on Boxing Day.
Reyes Cleary and Keillor-Dunn made it 2-0 to Barnsley in the opening 13 minutes before Louis Reed scored from the penalty spot for Mansfield.
The Stags levelled through Stephen McLaughlin early in the second half before Lewis won the game late on.
Stephen McLaughlin equalised early in the second half
Conor Hourihane made three changes from the side that were beaten 3-0 by lowly Exeter City just five days before Christmas.
Vimal Yoganathan replaced Adam Phillips, Josh Earl returned from injury to replace Tennai Watson while Neil Farrugia dropped to the bench and former Mansfield winger Caylan Vickers took his place.
It took less than two minutes for Reyes Cleary to open the scoring for the Reds.
The tricky winger was played through by Patrick Kelly and he fired past former Reds' 'keeper Liam Roberts to make it 1-0.
Keillor-Dunn doubled Barnsley's lead on 13 minutes thanks to a brilliant it of play between himself and Vickers - two former Mansfield players.
He fired in from 20 yards but didn't celebrate against his old club.
Luca Connell came close just five minutes later from a free-kick, which he won himself, but it went narrowly high and wide of the Mansfield goal.
Louis Reed, from Penistone, halved the deficit on 25 minutes from the spot after Reyes Cleary was adjudged by referee Martin Coy to have handled the ball in the box.
Murphy Cooper went the right way but could only get finger tips onto the penalty.
Barnsley then played themselves into even more danger just minutes later as Jack Shepherd passed back to Cooper who looked to have tripped a Mansfield forward but no penalty was given.
Cleary almost restored Barnsley's lead on the stroke of half-time after Luca Connell played a wonderful 40-yard cross-field ball to the winger who cut inside but could only see his effort go narrowly wide.
Barnsley came out the quicker of the two teams in the second half and Jonathan Bland came close to scoring his first goal for the Reds.
Kelly initially did well to find the young midfielder but his effort was straight at Roberts.
McLaughlin somehow bundled the ball home from inside the box after a huge scramble in the box to find the equaliser.
Aaron Lewis should have put the Stags in front minutes later but his effort was well over the bar from close range.
He did find the winner just minutes later as he fired past Cooper to send the away fans wild.
