Commonwealth Games gold-medallist Manoj Kumar's sensational upset win over a European champion left him just one step away from Olympic qualification but it was curtains for Suranjoy Singh as he was ousted following a second-round loss in the World Boxing Championships in Baku, Azerbaijan.

Manoj advanced to the pre-quarterfinals of the light welterweight division (64kg) with a thumping 19-7 win over European champion and fourth seed Raymond Moylette of Ireland.

Joining him in the next round from the Indian camp was Asian Games silver-medallist Dinesh Kumar in the light heavyweight (81kg) category.

The 12th-seeded Dinesh was declared winner at the fag end of his bout's final round as his rival Bosko Draskovic of Montenegro was disqualified for bending too much.

Both the Indian boxers now just have to win their next bouts to qualify for the London Games next year from the first Olympic qualifying event.

Top 10 boxers (from 49kg to 81kg division) will make the cut for the Games.

While Manoj will next face China's Qing Hu, Dinesh would be up against Australia's CWG gold-medallist Damien Hooper.

"Manoj fought very intelligently. He targetted this guy's body and invited him before coming up with his uppercuts and hooks. Dinesh was also very dominant throughout and even though Montenegro was not happy with the disqualification, the truth is that the guy was bending too much," national coach Gurbax Singh Sandhu said.

But it was curtains for CWG gold-medallist Suranjoy in the fly weight (52kg) division as he lost 14-17 to Mongolian ninth seed Nyambayar Tugstsogt in the second round.

Suranjoy, who lost to Tugstsogt by just one point on countback in the opening round of the previous World Championships, was leading by a point in the second round before the Mongolian came back to notch up the win in the rollercoaster bout.

Suranjoy, an Asian Games bronze-medallist, opened the proceedings for India and finished a point behind at 4-5 in the first round.

He roared back in the second round to clinch nine points against his rival's seven to make it 13-12. But Tugstsogt turned the tables in the final round to seal the issue.

"It is a very disappointing result. Even though Suranjoy fought back in the second round but in the final round, he got hit by a very nasty uppercut. That upset his rhythm and the Mongolian benefitted from that," said Sandhu.

Dinesh was next up and he established a 14-6 lead by the end of the second round before his rival was disqualified.