Reds 1 (Fletcher 73)
Fleetwood 1 (Davies o.g 60)
Ashley Fletcher made it a home debut to remember as he made sure the Reds head to Fleetwood in the second leg with the tie level at 1-1.
His fine 73rd-minute header restored parity after an enthralling second half of football at Oakwell.
It was a decent start for the Reds with the crowd behind them and Reece Wabara almost got in behind the defence on six minutes. The full-back's neat one-two with Winnall saw him burst into the area but Fleetwood cleared for a corner.
Fleetwood did enjoy some of the ball on 10 minutes as they patiently played their way forward but Ashley Hunter could only slice harmlessly over from the edge of the area.
On 12 minutes Barnsley came so close to breaking the deadlock through Conor Hourihane. Lloyd Isgrove did well to keep a corner alive by sliding the ball into Hourihane's path but his vicious effort was cleared off the line by Sarcevic.
At the other end Davies did well to keep out a McLaughlin cross but went one better in the next phase of play as Hunter let fly from 22 yards only for the Reds' number one to get across to his right and turn wide.
Bobby Grant bent in a delightful effort on the stroke of 18 minutes but his strike swerved wide of Davies' right-hand post.
Three minutes before the half-hour mark, Hammill found Wabara with a great threaded pass down the right and he, in turn, fed Williams but he could only fire straight at Maxwell.
Moments later Williams picked up on a poor Fleetwood pass before charging at goal although he scuffed his shot wide of the far post.
The visitors should have done better as Sarcevic and Proctor countered well together and the former went one-on-one with Davies only to drag wide on 39 minutes.
The second period started at a decent pace although both sides weren't giving much at the back. Jamie Proctor hammered well wide after surging in from the left whilst the Reds were struggling to carve anything clear cut at the other end.
Adam Davies did well to smother at the feet of Hunter whilst the Reds thought they'd found the net at the other. Hourihane's corner was punched towards his own net by Maxwell but a defender cleared off the line after the ball skimmed the underside of the bar. For a moment it seemed the ball had crossed the line but nothing was awarded with the linesman in a good position on 57 minutes.
On the hour the visitors took the lead. Isgrove charged forward down the right and took his time to pick out Williams but he scuffed his shot. Fleetwood countered and worked in a cross that was forced over the line as Davies tried to clear.
The Reds were flying forward with real purpose but lacking in any conviction as they approached the Fleetwood box.
On 68 minutes Lee Johnson rolled the first dice from the bench as Ashley Fletcher was introduced for his competitive and Oakwell debut, replacing Ryan Williams.
An Adam Hammill corner on 69 minutes was met by a brilliant header from Long but Fleetwood blocked his effort in the six-yard box.
On 73 minutes Oakwell erupted as Ashley Fletcher introduced himself to the Oakwell faithful with a superb header. Adam Hammill floated in a delightful cross that Fletcher rose highest to thunder in off the bar in front of the Ponty End.
The Reds got away with being caught in possession when Proctor shot straight at Davies on 83 minutes from inside the penalty area. The game was stretching in the closing stages as the rain came down on Oakwell.
Adam Davies again came to the Reds' rescue as Bell got lucky down the left when a pass crept through Isgrove's block, only for the Barnsley stopper to keep his shot out with his legs.
Barnsley were going for the jugular and White blasted at goal only to be denied by a good block moments before three minutes of stoppage time was added.
In the first minute of stoppage time, Reece Wabara did well to deny Fleetwood a late winner from Jamie Prcotor as he tried to steer in at the near post.
Reds: Davies, Wabara, A. White, Mawson, Long, Abbott, Hourihane, R.Williams (Fletcher 68), Hammill, Isgrove, Winnall.
Subs: Townsend, Bree, Fletcher, Templeton.
Fleetwood: Maxwell, McLaughlin, Pond, Davis, Bell, Jonsson, Sarcevic, Ryan, Grant (Forbes 70), Hunter (Haughton 76), Proctor.
Subs: Gogic, Jordan, Nirennold.
Referee: Frederick Graham.
Attendance: 11,403 (415 away)