Demetriou deflected in Hammill's shot for Barnsley opener
Winnall scored twice in two minutes
Second leg at Bescot on Thursday
Barnsley 0-0 Walsall
A moment of controversy at Oakwell as Lloyd Isgrove has the ball in the back of the net but is ruled offside.
The winger looks to have timed his run to perfection and seem to be being played onside by a Walsall full-back.
The home crowd are not happy.
Barnsley 0-0 Walsall
Lloyd Isgrove continues to enjoy plenty of space down the right and his attempted cross is sent away for another Barnsley corner.
The hosts are given three chances to put the ball into the box before Neil Etheridge claims the ball for the away side.
Barnsley 0-0 Walsall
Tim: I live in Leeds and support Ipswich so I'm hoping for a Barnsley v Bradford final #easyawaydays
Kai Tolley: Come on Walsall! Let's see some goals today!
Ian Fearing: Think the general feeling of Burton fans is we'd like Walsall to join us, another smallish club punching above its weight.
Walsall were pipped to automatic promotion by Burton, who went on an open-top bus tour around the town earlier today...
Image source, Rex FeaturesBarnsley 0-0 Walsall
A quiet 15 minutes and all of the sudden the game has sparked into life.
Barnsley winger Lloyd Isgrove collects the ball 25 yards out and unleashes a fierce shot which is just tipped away by Neil Etheridge.
The resulting corner is collected well by the Walsall goalkeeper.
Barnsley 0-0 Walsall
Walsall have settled and are starting to enjoy a bit more time on the ball but they're yet to do much with it in the final third.
Both sides feeling each other out for the time being.
Barnsley 0-0 Walsall
BBC Radio 5 live sports extra
You can listen to BBC Radio Sheffield's commentary from Oakwell on BBC Radio 5 live sports extra by clicking on the audio icon at the top of the page.
BBC WM 95.6 are also broadcasting live commentary of this League One play-off semi-final first leg - unfortunately we're unable to stream that on our website.
Image source, Rex FeaturesBarnsley 0-0 Walsall
Visitors midfielder Kieron Morris makes a surging run from the middle of the park but can't get his shot away as he's crowded out by the Barnsley defence.
Neither side has troubled either keeper yet.
Barnsley 0-0 Walsall
Walsall haven't managed to get out of their half yet and Barnsley midfielder Lloyd Isgrove sends in an inviting cross from the right that just evades Sam Winnall in the box.
The hosts are certainly on top at the moment.
Barnsley v Walsall, 17:30 BST
Image source, Rex FeaturesIf you've got any thoughts on Barnsley, Walsall or the League One play-offs, then please send them my way.
Who's your money on to join Wigan and Burton in the Championship next season?
Get in touch using #bbcfootball on Twitter.
Barnsley 0-0 Walsall
Barnsley attack down the right early on and Walsall struggle to get the ball away from the box.
The ball is eventually cleared with Tykes striker Sam Winnall lurking.
Barnsley 0-0 Walsall
Walsall get us under way at a rowdy sun-drenched Oakwell.
Barnsley v Walsall, 17:30 BST
Quote MessageI'd like to see Walsall go out and win. Go and attack, play your normal game, and go on from there.
Jimmy Walker, Ex-Walsall goalkeeper at Oakwell, BBC WM 95.6
Barnsley v Walsall, 17:30 BST
Image source, .Walsall, unsurprisingly, select the same starting line-up that won 5-0 at Port Vale on the final day of the regular season.
Subs: MacGillivray, Taylor, Mantom, Preston, Cook, Osbourne, Hiwula.
Barnsley v Walsall, 17:30 BST
Quote MessageYou don't see unchanged teams too much these days, but it gives the players in the side confidence and it gives those on the touchline an edge to get in there, win a place and stay in the side.
Derrick Parker, Ex-Barnsley striker at Oakwell, BBC Radio Sheffield
Barnsley v Walsall, 17:30 BST
Image source, .Barnsley are unchanged from Sunday's 4-1 win at champions Wigan, a result that secured a League One play-off spot for the Tykes.
Subs: Townsend, Cowgill, Chapman, Toney, McCourt, Tuton, White.
Barnsley v Walsall, 17:30 BST
Image source, Rex FeaturesWalsall narrowly missed out on automatic promotion to the Championship, despite beating Port Vale 5-0 on the final day, as Burton claimed the point they needed to finish second.
Following Sean O'Driscoll's shock sacking, Jon Whitney has overseen eight victories in his 12 games from when he took charge in early March.
The Saddlers will be looking to top scorer Tom Bradshaw, who has netted 17 league goals in this season campaign, to provide the spark today.
Barnsley v Walsall, 17:30 BST
Image source, Rex FeaturesBarnsley were floundering at the bottom of League One in December but won 13 of their next 19 league matches to push themselves into the play-off places by March.
Despite manager Lee Johnson leaving the Tykes in mid-February caretaker boss Paul Heckingbottom guided them to victory in the Johnstone's Paint Trophy final over Oxford at Wembley in April.
A 4-1 victory away at champions Wigan on the final day of the season secured the last play-off place on goal difference ahead of Scunthorpe.
Barnsley v Walsall, 17:30 BST
Play-off matches always have a special feeling attached to them and today's League One tie at Oakwell will be no different.
Both Barnsley and Walsall will be looking to draw blood first and move a step closer to Wembley, in a game that will hopefully be full of goalscoring opportunities, tasty tackles and individual pieces of magic.
You can follow all of the action on this sunny late afternoon in South Yorkshire here.