A Ukranian shooter has cost her teammate the chance at a medal by oversleeping and missing a critical round of the 10m air pistol international mixed team event of the Nanjing Youth Olympic Games at the Fangshan shooting hall on Thursday.

Ion Aric of Moldova and Polina Konarieva of Ukraine were in the chase for a medal, but their chances were scotched by Konarieva's late arrival after waking up late.

The pair had beaten Margarita Lomova of Russia and Juan Sebas Rivera Ruiz of Colombia, 10-9, on Wednesday, to make the quarterfinals and the duo looked poised to challenge Zaven Igityan of Armenia and Chung Ting-yu of Chinese Taipei for a place in the semifinal.

But Konarieva's absence left the result null and void. The message "DNS" (did not shoot) appeared near the duo's score and gave their opponents free passage into the semifinals. Konarieva reached the venue but competition had already begun. She was present at the shooting hall when the medals were awarded later in the day.

"I don't know what to say to him," she said, referring to Aric. Her coach, Alexander Kaminskyy of Ukraine, explained why she didn't reach the venue on time for the start of the competition.

"She was sleeping and woke up at 8 o'clock and went to the station to get a taxi. The driver didn't know the road but he said, 'OK, I know, shooting range ... no problem'," he said.

"I think it is my mistake," Kaminskyy said.

Aric, who was clearly upset during the quarterfinals, was inconsolable as he left the venue before the finals.

"Yes, there was a lot of emotion ... I did not know how to feel. "Why she was late, I don't know why ... she is not responsible for her action. I'm a little angry," he said.

Jorg Brokamp of Germany, the ISSF technical delegate present blamed carelessness for the error. "It's not the fault of the shooter but the fault of the team manager and coach. That's the first duty as a coach and manager, you have to prepare your athletes schedule and get all the necessary information," Brokamp said.