The 29-year-old Indian went down 3-0 in the contest which was not particularly engaging in its quality of boxing but showcased Manoj's fighting spirit.
The 25-year-old Gaibnazarov, the World and Asian Championships silver-medallist from Uzbekistan, was consistently better than Manoj but the Indian impressed with his never-say-die spirit.
In the opening round, Manoj kept his rival at a distance, denying him a clear shot. The dodge-first-attack-later strategy managed to unsettle the Uzbek for sometime but it was never going to be enough and Gaibnazarov clinched the initiative with a couple of left jabs in the closing seconds.
In the second round, Gaibnazarov continued to rely on his strong left, prompting a standing eight count against the Indian. The Uzbek's foot movement was lucid after he had clearly got a hang of the Indian's strategy and he connected much better.
Manoj was guilty of not using his height and reach advantage to the fullest and was clearly shaken by a vicious blow to his torso by Gaibnazarov's powerful left hand.
To Manoj's credit, he never seemed short of spirit or energy despite the blows he was taking from Gaibnazarov.
The Haryana lad was way more aggressive in the final round but Gaibnazarov's footwork and tremendous balance while back-peddling negated the attempted attacks.
Gaibnazarov was the clear winner for all the judges but in a fine sporting gesture, he embraced Manoj and lauded his effort in the bout.
With Manoj and Shiva Thapa (56kg), who lost in the opening round, ousted from contention, India's boxing campaign now comprises only Vikas Krishan (75kg).
Vikas is scheduled to fight his quarterfinal bout tomorrow.