At 3.40pm, Wednesday were trailing 1-0 – it should have been worse – were bereft of heart and desire, and boos were starting to cascade down from the Hillsborough stands such was the ineptitude on display.

The Owls were four points adrift of safety before kick-off and the opening 40 minutes suggested they had already accepted their fate. Defeat here and relegation would have been looming closer to reality.

Step forward manager Brian Laws. When many would have waited until half-time to give his players a roasting, angry Laws hauled off Enoch Showunmi and Ronnie Wallwork with five minutes of the first period remaining and replaced them with Sean McAllister and Deon Burton.

Showunmi had been guilty of spurning Wednesday's best chance – running through on goal he checked and tried to beat a covering defender instead of shooting – while the attempt to pair Wallwork with fellow veteran Graham Kavanagh failed once again to provide the midfield with legs, as QPR danced rings round the pair.

It was a calculated gamble by Laws and he was repaid handsomely.

Suddenly, there was urgency injected into Wednesday's performance, McAllister in particular coming of age in midfield, and Kavanagh capped it off by grabbing an equaliser just before the break.

On-loan Franck Songo'o celebrated his debut by crossing for fellow loanee Kavanagh to head home after goalkeeper Lee Camp came but failed to reach the ball.

The boos turned to cheers at the interval whistle and the new-found belief seeped through to the second half.

Good work between Marcus Tudgay and Burton – the pair are Wednesday's best partnership but too often fail to deliver the goals their approach play deserves – saw McAllister burst into the area.

Camp dived at the youngster's feet and referee Neil Swarbrick pointed to the spot.

Burton obliged with a low shot to Camp's right to secure an improbable victory for the home side after such a poor start.

The visitors, who had taken the lead when Damien Delaney netted Rowan Vine's cross, were thwarted by Lee Grant who did well to deny Dexter Blackstock's header.

With better finishing, the Owls could have further extended their lead, the closest they went to achieving that aim when Kavanagh was denied by Camp.

"I am very disappointed with that first half hour because we are in the mire. We are in the bottom three and that performance wasn't going to get us out," Laws said. "But, having said that, I'll take responsibility because I pick the team and today I hold my hands up and say I got it wrong.

"It's not just the two players (who were substituted) that were at fault, but it was the whole performance, but I will take responsibility for that, not the players.

"The second-half performance was much more like it, it gave us the energy in the middle of the park while Deon Burton gave us the quality in holding the ball up.

"We needed a spark and we didn't get one in the first half and I felt we needed to give the crowd a lift as well. Call it brave, call it stupid, call it what you like I will take responsibility, I got it wrong.

"I thought it sent a message to show we are not down and out and we are prepared to take the risk at that particular time because we weren't good enough.

"My coaches weren't really wanting me to do that (make the double-substitution) at that time but I thought it might just give us some impetus and rather than have the crowd booing us at half time I wanted to give them a lift."

Victory leaves the Owls two points adrift of fourth-from-bottom but with two games in hand. Tomorrow they travel to basement club Colchester.

Sheffield Wednesday: Grant, Hinds, Beevers, Wood, Spurr, Kavanagh, Small (O'Brien 90), Wallwork (McAllister 40), Songo'o, Tudgay, Showunmi (Burton 40). Unused substitutes: Burch, Boden.

QPR: Camp, Delaney, Stewart, Mancienne, Connolly, Rowlands, Leigertwood (Mahon 66), Buzsaky (Balanta 75), Blackstock, Agyemang, Vine (Ephraim 63). Unused substiutes: Pickens, Rehman.

Referee: N Swarbrick (Lancashire).

Owls man of the match: Graham Kavanagh