USA WINS MEN'S 4X100M – IAAF/BTC WORLD RELAYS, BAHAMAS 2015

Justin Gatlin, Mike Rodgers, Tyson Gay, Ryan Bailey, the US quartet did what so many of their predecessors have failed to do in this event in recent years, get the baton round cleanly, and that allowed them the opportunity to inflict a morale-boosting defeat on the favoured Jamaicans, the Americans winning in 37:38.

In history it was the equal-seventh fastest performance and a time only other US and Jamaican teams have ever beaten.

From midway down the back Jamaica was left trailing in the wake of the US runners and the 2014 World Relays winners were left to settle for second on this occasion in 37.68, also inside the previous competition record.

Justin Gatlin remains a polarising figure in the sport but has to be given credit for delivering the win with a blistering second leg, pulling away from Jamaica's Kemar Bailey-Cole almost immediately after the first exchange and then putting a huge margin between himself and the rest of the field.

Around the bend, Tyson Gay consolidated the US lead and handed over several metres in front to Ryan Bailey.

Usain Bolt, a sprinter of stunning talent, this was too big a margin to make up and though he reduced the deficit by a metre or so, in the end the reigning world and Olympic champion in the 100m and 200m was a minor player in this drama.

Japan, almost unnoticed, showed off their slick baton passing skills, after being given a great start by their lead-off runner Kazuma Oseto, and came through for a slightly unexpected bronze medal in 38.20.

All eight finalist however, went away with a prize from Nassau, automatic qualification for this event to the Rio 2016 Olympic Games.

The USA had shown that they would be the team to beat when they won their heat time in 37.87, despite a slightly ragged handover from Gay to Bailey.

Jamaica by contrast, won their heat in what for them was a relatively modest 38.07, with Bolt easing down over the final 10 metres on the anchor leg.

Third in 2014, Great Britain, made a surprise departure in a rather loaded second heat, with the first two changeovers being far from perfect, and despite world and European indoor 60m champion Richard Kilty making up ground on the last leg.

They didn't progress to the main final, but finished fourth.

With some poor changeovers in evidence once again, they got a small amount of consolation by winning the B-final, but Kilty ran strongly on the final leg to bring them home in front in 38.67, just edging again  Barbados' Mario Burke over the final 10 metres, the latter anchoring the Caribbean Island to a national record of 38.70.