Birmingham will go into the final match of the Sky Bet Championship season with the threat of relegation still hanging over them following a 3-1 defeat to QPR at Loftus Road.Belgian youngster Ilias Chair scored his first senior goal midway through the second half and Matt Smith added a third in stoppage time to secure the Hoops a deserved victory.Bright Osayi-Samuel also scored his first QPR goal to haul them level less than two minutes after Che Adams had opened the scoring.The visitors went ahead in the 27th minute when Jacques Maghoma sent in a low cross from the left and Adams slotted home his eighth goal of the season.But Maghoma was quickly given a taste of his own medicine, with Luke Freeman beating him on the flank to set up Rangers' equaliser.Chair directed Freeman's right-wing cross back towards Osayi-Samuel, who scored from close range with the aid of a deflection off Blues defender Wes Harding.Freeman and a deflection were also involved in QPR's second goal?, scored in the 70th minute. ?Again Freeman created space for himself on the left and crossed to Chair at the far post, where the midfielder's shot went in off Blues defender Maxime Colin.And Smith, on as a substitute, fired in off the post after being teed-up by Ebere Eze's header.Birmingham goalkeeper David Stockdale had kept Rangers at bay with a number of saves.Stockdale denied Ryan Manning, Eze and Freeman early on and denied Osayi-Samuel a second goal before the interval by tipping over the winger's powerful shot.His best stop came early in the second half when he superbly parried Jake Bidwell's header from Freeman's corner and an off-balance Darnell Furlong was unable to add the finishing touch from close range.Stockdale also did well to push over a fierce strike from Freeman before Rangers finally grabbed the lead.Stockdale later denied? Jamie Mackie, while R's goalkeeper Joe Lumley prevented a Birmingham equaliser by getting down quickly to grab a shot from Jota.Nedum Onuoha and Mackie were given rousing receptions by the home fans when they were brought on as second-half substitutes. Both players are leaving QPR when their contracts expire this summer.The mood among Blues fans is much more sombre. Their team will go down if they lose at home to promotion-chasing Fulham next weekend and results elsewhere go against them.