China unfortunately lost the chance to enter the women's 4x100 meters final at Rio Olympics with a narrow gap behind the Canadians after the US successfully appealed its second chance to race alone on Thursday morning local time.

The defending champion cracked 41.77 seconds for the second chance, sending China out of the original finalists, among which its result of 42.70 seconds was placed last behind the Canadians' by six thousandths of a second.

The Chinese delegation tried in vain to protest against the decision but said it respected the outcome.

Allyson Felix of the US team bungled the second baton exchange but the defending champion appealed that the four-timeOlympic gold medalist had been bumped by a Brazilian athlete before the handover.

The United States will join arch-rivals Jamaica, Britain, Germany, Ukraine, Nigeria, Trinidad and Tobago and Canada in Friday's final.