Thanks to the the absence of the world record co-holder Asafa Powell, who chose to run only in the relay, Gay ran very close to his personal best of 9,85. The world record is 9,77.

The 24-year-old's time of 9.88 into a 1.1 meter per second headwind was enough to see off European champion Francis Obikwelu and Trinidadian Mark Burns, who was the Americas's replacement for world record holder Asafa Powell.

Powell almost saw some action in the 4x100 meters relay but his Americas team mates dropped the baton before it reached him.

The World Cup brings together teams from Africa, the Americas, Asia, Europe, Oceania and the U.S. plus three European nations -- Russia (men and women), France (men), and Poland (women) who qualified via the European Cup -- plus hosts Greece.

Another American, LaShawn Merrit, reversed last weekend's result in Stuttgart when he beat African champion Gary Kikaya in the 400 meters, while Kerron Clement took advantage of the absence of European champion Pericles Iakovakis - absent with a hamstring injury -- to win the 400 meters hurdles.

The U.S. completed a sweep of the day's sprint events by taking the short relay with Gay running the final leg.

However, they still finished the first day -- the halfway point in the competition -- two points behind Europe who benefited from Ralf Bartel's win in the shot put and Tomas Janku's victory in the high jump.

Kenyan Alex Kipchircher helped Africa into third place by adding the 1500 meters to a long list of successes in 2006.

He won gold medals at last week's World Athletics final in Stuttgart at 1500, the African Championships at 800 and 1500 and the Commonwealth Games in the 800 meters.

Saif Saaeed Shaheen, running for Asia, took the 5000 meters.

The women's competition is evenly balanced with Russia and the Americas level on 65 points, five ahead of Europe.

The Americas had a great day on the track with sprinter Sherone Simpson running 10.97 in the 100 meters to hold off Torri Edwards, the U.S. replacement for Marion Jones who had decided she was not fit enough to run in Athens.

Cuban Zulia Calatayud came home ahead of the Kenyan Janeth Jepkosgei in the 800 metres for the second time in a week.

Sanya Richards set a U.S. record in the 400 meters. Her time of 48.70 seconds broke Valerie Brisco's national record set when she took gold in Los Angeles in 1984.

"I was just overwhelmed. I can't believe it is a national record.I am so happy," said Richards whose time was the fastest in¡¡the world since the 1996 Olympics in Atlanta.

Russia's Yelena Isinbayeva had arguably the most comfortable evening, needing just one jump to win the women's pole vault at a height of 4.60 meters.

Isinbayeva, however, looked extremely disappointed at not being able to raise the bar immediately to five meters and failed three times at 4.80 as she challenged her world record.

Fellow Russian Tatyana Lebedeva edged Greece's Hrysopiyi Devetzi in the triple jump as both cleared 15 meters.