Competition in the second round of the ASP event in Portugal was suspended until 1:30pm (local time) but not before Kelly Slater was eliminated.

The American was taken down by local hope Frederico Morais 12.34 to 10.13 before the high tide at Supertubos caused inconsistent surf.

The loss hit him extra hard as his main competitor in the race for a 12th world championship, Australian Mick Fanning, had previously gone through comfortably.

Fanning won his heat over another local, Francisco Alves, 13.00 to 8.93.

The 2007 and 2009 world champion lead Slater by 6,000 points in the title race.

South Africa's Jordy Nelson and fellow Australians Taj Burrow and Joel Parkinson are the next closest competitors but would most likely need to win the tournament in Portugal and hope Fanning misses the semi-finals to have any title hope.

Australians Adrian Buchan, Adam Melling and Bede Durbidge were forced to wait until conditions improved to get their heats underway.

Supertubos is the second-last stop on the World Championship Tour which will wrpa up at Pipe Masters in Hawaii in December.