Republic of Ireland are still in the race to Russia, insists O'Neill
Republic of Ireland boss Martin O'Neill still believes his side can qualify for the 2018 World Cup despite losing 1-0 to 10-man Serbia.
Aleksandar Kolarov's thundering strike dropped the Republic to third in Group D after Wales' 2-0 win over Moldova.
O'Neill's men are without a win in four qualifying games, but the Ulsterman still thinks qualification for Russia is within reach.
O'Neill said: "I'm very disappointed, naturally, but very proud of the team which is very important. We have two games left and we can still make it."
Kolarov's 55th-minute piledriver guaranteed his side a top-two finish in Group D despite defender Nikola Maksimovic's 68th-minute red card.
But the Republic were furious not to be awarded a penalty for Jagos Vukovic's challenge on substitute Daryl Murphy six minutes later as Turkish referee Cuneyt Cakir waved away their appeals.
Martin O'Neill's misery was compounded by Wales' 2-0 victory in Moldova, which means the Republic now sit third in the group with just two games to play, and with key men Robbie Brady and James McClean suspended for the Moldovans' visit to the Aviva next month.
On a night when victory was the only real option, Glenn Whelan and Harry Arter paid the price for their side's poor first-half display in Georgia on Saturday as David Meyler and Wes Hoolahan, who had been nursing a groin problem, were drafted in.
Ulsterman O'Neill also opted to tinker with his system, handing Hull midfielder Meyler the task of patrolling the space in front of his back four at the base of a diamond which had creator in chief Hoolahan at its peak, and his boldness was rewarded with a much improved performance.
There was an early scare for the Republic when Meyler surrendered possession inside his own penalty area and Shane Duffy had to hurl himself into the path of Nemanja Matic's well-struck drive.
Central defender Duffy saw a 10th-minute header correctly ruled out for offside after Brady and Hoolahan had worked a short corner move, and Serbia keeper Vladimir Stojkovic was relieved to get his fingertips to Shane Long's stinging 20th-minute effort.
Long, the victim of some robust treatment from the Serbian defence, failed to extend Stojkovic as much as he might have after being played into space down the left and cutting across Branislav Ivanovic with 53 minutes gone.
However, it was the visitors who were celebrating within two minutes when Filip Kostic guided the ball perfectly on to the fast-arriving Kolarov's left boot and he dispatched it off the underside of the crossbar with a venom which left Darren Randolph helpless.
It was not to universal approval that Hoolahan departed to be replaced by striker Murphy with 28 minutes remaining, and the new man made a swift impact.
As he set off in pursuit of Brady's ball over the top, last man Maksimovic slipped and was adjudged to have brought him down, prompting Mr Cakir to brandish a red card, although Brady wastefully drilled the resulting free-kick into the defensive wall.
Murphy was convinced he should have been awarded a 76th-minute penalty for a challenge by Vukovic as he tried to meet substitute Callum O'Dowda's teasing cross, and saw an 86th-minute snapshot palmed away by Stojkovic.
Rep of Ireland: Randolph, Christie, Duffy, Clark, Ward (O'Dowda, 72 mins), Hoolahan (Murphy, 62 mins), Meyler (Hourihane, 79 mins), Brady, Walters, S Long, McClean. Unused subs: Westwood, O'Shea, Keogh, Whelan, Horgan, K Long, Hayes, Arter, Elliot.
Serbia: Stojkovic, Vukovic, Maksimovic, Ivanovic, Rukavina, Milivojevic, Matic, Kolarov, Kostic (S Mitrovic, 72 mins), A Mitrovic (Prijovic, 79 mins), Tadic (Gudelj, 81 mins). Unused subs: Rajkovic, Obradovic, Nastasic, Tosic, Gacinovic, Spajic, Radoja, Ljajic, Jovanovic.
Referee: Cuneyt Cakir (Turkey)