The Owls gave a classy West Bromwich Albion a real scare in the second half but just as Leeds United were turning a 1-1 scoreline into a 2-1 lead late on at Luton Town, so the team top of the Championship were doing the same to Garry Monk's side.
For much of the first half, it looked like Hal Robson-Kanu's tenth-minute goal had burst Wednesday's balloon but the came on strong after the restart... just not quite strong enough.
The Wales striker's goal gave a fluid West Brom side a lead that only looked in any danger when Kadeem Harris was on the ball during the opening 45 minutes. But the second period was a different story with Steven Fletcher equalising from the spot and Morgan Fox hitting the crossbar, only for the Owls's indiscipline to cost them a point as Charlie Austin converted a penalty of his own after 86 minutes.
Harris looked dangerous from the off, sprinting onto Fox's hopeful second-minute ball, but a sliding Fletcher was unable to make contact with his cross. He was at it again down the right after five minutes, winning Wednesday a corner seconds after they had defended one at their end.
When Liam Palmer played Kieran Lee in, Sam Johnstone rushed out and saved his chipped effort.
Then West Brom went in front.
They too had their moments at 0-0, and Dominic Iorfa had defended well to stop Robson-Kanu breaking clear in the eighth minute, but even matching the hosts's five-man midfield, the Owls found their movement hard to cope with, and when the impressive Matheus Pereira threaded a lovely ball through two minutes later, Robson-Kanu was able to run onto it impeded and slip the ball through Kieren Westwood's legs.
What had been an entertaining game became very bitty, with referee Tony Harrington too intolerant of Wednesday's attempts to get close to their constantly-moving men. Lee was booked for bringing down Filip Krovinovic, and Sam Hutchinson for a tackle which seemed to be suffering from a satellite delay, but there was no punishment when Kyle Bartley caught Fletcher with a flailing arm. Of 13 free-kicks awarded in the opening 45 minutes, 11 went West Brom's way. The ironic applause from 2,000 away fans when Wednesday got a decision midway through the half was like they had scored a last-minute winner, not won a free-kick in their own half.
Fletcher's frustration saw him concede a clumsy free-kick on the edge of the area, but Pereira put it into the wall. Grady Dianga also missed a good chance, dragging his shot badly wide to his obvious anger.
When Harris nutmegged Bartley at the other end Furlong was quickly across to snuff out the danger. That Johnstone's only first-half save was not even forced by one of those in green said a lot about how Harris's team-mates had been blunted at that stage
Not for the first time, they looked unsure of what to do with the ball within striking distance of the West Brom goal, but Furlong's clearance hit Matty Phillips and had the goalkeeper sprawling to save his colleague's embarrassment.
With Harris becalmed to the point where he was substituted after an hour, Wednesday came out for the restart much improved with their attacks focused down the right.
When Jacob Murphy beat Grady Diangana in the 50th minute, Johnstone spilled the cross, but Ahmed Hegazi was the only player to react.
Complacency seemed the biggest threat to the Championship leaders, and Filip Krovinovic conceded a 58th-minute penalty when he was caught overplaying, and bundled Lee to the ground in panic. Fletcher fired the penalty down the middle while Johnstone dived left.
When Fox volleyed Barry Bannan's free-kick against the crossbar, West Brom overplayed at the goal-kick and it took a desperate Hegazi block to stop Lee capitalising.
Robson-Kanu had two good chances before that for the Baggies, first putting a right-wing cross wide under pressure, then narrowly failing to connect with another.
But Slaven Bilic has a deep bench, and replaced the goalscorer with Austin. Gareth Barry and Chris Brunt also came off the bench as the Croatian manager refused to settle for a point.
Within a minute of heading against the post Austin was standing over a penalty. Westwood had rushed from his line as Pereira was played over the top and conceded the spot kick. Austin slammed it home.
Just as Wednesday could have no complaints about the penalty, so they could not argue with the red card which rules Liam Palmer out of Wednesday's visit of Monky's previous team, Birmingham City.
Or so you would have thought.
Palmer went off pointing an accusing finger at Pereira as if the midfielder, not a reckless tackle on Diangana near the corner flag, had been responsible for for Harrington's decision in the second added minute.
Wednesday had 15 shots to West Brom's nine, but lacked that extra something which means the Baggies will be pushing Leeds and others hard for the title after Christmas, while Wednesday will probably have to aim for the play-offs. Without a win in four, they are currently four points away.
West Bromwich Albion: Johnstone; Furlong, Bartley Hegazi (Barry 78) Townsend; Ajayi; Phillips, Krovinovic (Brunt 81), Pereira, Diangana; Robson-Kanu (Austin 78).
Unused substitutes: Gibbs, Zohore, Edwards, Bond.
Sheffield Wednesday: Westwood; Palmer, Iorfa, Borner, Fox; Murphy, Lee (Luongo 70), Hutchinson, Bannan, Harris (Reach 60); Fletcher.
Unused substitutes: Lees, Nuhiu,Odubajo, Dawson, Forestieri.
Referee: T Harrington (Cleveland)