NOTTINGHAM Forest got their play-off push back on track as an own goal from Miguel Llera decided a closely fought contest with Sheffield Wednesday.
On a day when both sides missed numerous opportunities, the game's decisive moment came as the Spanish defender headed into his own net in the 74th minute.
Forest had failed to win their previous three matches, but pulled themselves back to within a point of the top six as they ground out a battling 1-0 win over the Owls, who had made them defend doggedly at times to preserve their clean sheet.
A frantic start to the game saw both sides carve out numerous chances in the first eight minutes with the only question mark being over how it had remained goalless.
Blackstock, restored to the side with Simon Cox having collected a slight injury on international duty, fed an incisive pass for strike partners Billy Sharp and, while he just failed to get the ball under control, Chris Cohen still headed wide after Greg Halford had swung the ball back into the danger zone.
A poor pass from Elliott Ward gave Gary Madine the chance to run at the Forest defence and force a fine save from Lee Camp, plunging low to his right, with a powerful low shot.
The Forest keeper had to be at his best again as more uncertain defending allowed Jose Semedo to power a shot towards the near post, where Camp produced an even better stop.
Andy Reid was denied by the fine reactions of Chris Kirkland in the Wednesday goal after a swift passing move had taken the Forest winger through on goal, where he attempted to lift a shot over the advancing keeper, who did well to palm away.
Danny Collins had to come up with a vital challenge to deny Jay Bothroyd a shooting chance after the striker had drifted into space on the edge of the box, but Forest hit back immediately again as Sharp produced a neat turn and shot on the edge of the box that was charged down.
Ward almost got caught out when he attempted to nutmeg Bothroyd, despite the fact that he was the last man in the Forest defence. But, again, the home side were a threat on the break and saw a Reid cross come agonisingly close to picking out the run of Sharp towards the far post, before a last ditch interception changed the course of the ball.
Sharp and Blackstock were looking lively, with Sharp then eluding two players down the left and delivering into the centre where Blackstock came close to connecting.
Brendan Moloney produced a goal saving piece of defending after Lewis Buxton seemed to benefit from a generous offside decision to surge down the right flank and deliver into the centre where Bothroyd was waiting to pounce until the Irish defender conjured up a superb challenge to clear.
Jenas broke quickly from midfield, despite referee Andy Woolmer getting a touch on the ball, and saw his effort to curl the ball inside the far post take a deflection for a corner.
Forest were building a short spell of pressure, with Reid delivering an outstanding cross to the far post where Anthony Gardner cleared with a brave header as Blackstock challenged purposefully.
Another good interchange saw Blackstock provide a neat layoff for Sharp, whose shot took a clear deflection on the way wide of the post – but referee Woolmer failed to spot it and awarded a goal kick.
When Cohen swung in a delightful ball from the right, after cutting back on to his left foot, Sharp looked certain to score, but Jenas dived at full stretch and, while managing to get a slight touch on the ball, succeeded only in guiding it away from his team mate.
Nejc Pecnik made a meal of a good chance as Wednesday threatened from one of their numerous first half corners. Forest had generally defended set pieces very well against a tall opposition side. But the Owls man managed to find the space to unleash a powerful shot when the ball dropped to him, which flew narrowly over the bar.
Forest suffered an early blow in the second half when Reid sustained an injury and had to be replaced by Henri Lansbury, while Wednesday made a change of their own as Pecnik was replaced by Jermaine Johnson.
Jenas' first start since re-joining Forest was to last less than an hour as he was replaced by Adlene Guedioura. But it was Lansbury who was to have an immediate impact, as he let fly with a long range shot that Kirkland had to react quickly to save.
While the keeper also did well to hold on to a bending shot from Cohen as Blackstock charged in to pick up any spillages a few yards from goal.
It was the Owls who twice failed to capitalise on outstanding chances however. Firstly, Collins had to make a vital interception on the line after a darting run from Daniel Jones saw him lure Camp off his line before cutting the ball back for Bothroyd to shoot, only for the Forest skipper to head clear.
Michail Antonio then blazed an even better chance high and wide from close range after Forest had failed to clear.
Forest demonstrated the same wasteful habits themselves after Lansbury had exchanged a clever one-two with Blackstock, but then rifled his shot a foot over the bar with the goal at his mercy.
Guedioura tried his luck with a trademark shot from distance that, with numerous bodies in the box, did cause a nervous moment for the visiting defence, even as it flew well wide of the upright.
Blackstock came within a whisker of snatching a goal when Gillett fed the ball down the centre, but the striker failed to get the important touch that would have steered it beyond Kirkland.
Cohen had been finding the room to fire some telling balls into the box from the Forest right and, when the midfielder loped into space again in the 74th minute, his precision was to play a key role in the opening goal.
With Blackstock and Sharp waiting to pounce in the centre, Llera attempted a desperate headed clearance, at full stretch, which deflected the ball into his own net.
A clever corner routine might have secured a second for Forest, with Cohen having driven the ball powerfully towards the near post where, leaning back slightly, Lansbury lifted his shot over.
With the Owls pushing men forward in search of an equaliser, Sharp almost struck on the break, with Kirkland needing to show quick feet to claim a lofted shot from the striker
Sub Danny Mayor also had Camp looking on with a slight sense of nervousness as he let go with a long range shot that flew only a few feet away from the target.
But, following one of the best passing moves of the game for Forest, Cohen then side-footed a shot inches wide at the other end.
Llera's afternoon was only made worse when, in the 90th minute, he became the first player to be booked, for a foul on Blackstock.
Forest: Camp, Moloney, Ward, Collins, Halford, Gillett, Cohen, Jenas (Guedioura 55), Reid (Lansbury 50), Sharp, Blackstock. Subs: Darlow, Guedioura, McGugan, Cox, Coppinger, Ayala.
Sheffield Wednesday: Kirkland, Buxton, Jones, Llera, Gardner, Barkley, Semedo (Mayor 82), Madine, Antonio, Bothroyd, Pecnik (Johnson 52). Subs: Bywater, Taylor, Mattock, McCabe, Rodri.
Referee: Andy Woolmer
Attendance: 24,584 (4,405 away)