KEY POINTS:
Mick Fanning's world title dreams have been put on ice with challengers Kelly Slater and Taj Burrow joining him in the Billabong Pro semi-finals.
Fanning could have secured his maiden world title, and the first for an Australian since 1999, if he won in Spain and both Slater and Burrow failed to reach the final four.
But the eight-times world champion Slater, from the United States, and Australian Burrow ensured a massive final-day showdown by joining Fanning and defending event champion Bobby Martinez in the semifinals.
Helping Fanning is the fact Slater and Burrow have drawn each other in the semifinals, likely to be held today.
"It works out pretty good for Mick with me and Kelly on one side of the draw doesn't it?" Burrow said after his quarter-final win over compatriot Bede Durbidge.
Slater narrowly defeated Frenchman Jeremy Flores in his quarter-final while Fanning slayed American Taylor Knox. Had Slater lost to Flores he would have been out of the title hunt and it would have guaranteed an Australian world champion.
But the world's greatest surfer is still lurking ominously. "I won that heat and I have to go to Brazil now," Slater said. "Sometimes it's hard to define exactly what you have to do, but right now I know exactly what I have to do. I have to go to Brazil and I have to win, that's about it.
"If I lost that heat it would have been an Australian title no matter what, but I think surf fans around the world want to see the race continue for a little bit longer, no matter who wins it. Mick is in the driver's seat and Taj and I are just along for the ride trying to catch up to him; trying to draught him, so to speak."
Fanning's semifinal berth in Spain is his ninth in the past 13 events. He's won two events this year, including the previous contest in France, and will be hard to beat for the world crown if he wins another.
"You have to keep the pressure on, it's not over yet," Fanning said. "I've got Bobby Martinez next. He's the defending champ and he has been surfing insane [in] this event."
Martinez earned the highest wave score of the event thus far, a 9.70 out of 10.00, for slotting himself into the only real barrel ridden in this year's wave-starved event in his quarter-final win over Australian Phil MacDonald.
-AAP