The United States women's 4x100m team will get a chance to qualify for the final after winning the right to re-run their heat in Rio this morning (Singapore time).

The defending champions were facing a sensational disqualification after a dropped baton changeover involving Allyson Felix and English Gardner.

However USA Track and Field appealed after it emerged a Brazilian runner had bumped into Felix as she approached for the changeover.

The heat had been won by Germany's quartet in 42.18sec ahead of Nigeria, Trinidad and Tobago, and Brazil, who were disqualified. In the other semi-final, Jamaica won in 41.79sec.

The US have to beat the fastest losers' time of 42.70.