Israeli brother and sister pair of Alexandra and Roman Zaretski finished the first day of the Ice Dance competition at the World Figure Skating Championships in ninth position. The top Israeli duo scored 32.51 points with their Argentine Tango in the compulsory dance. France's Isabelle Delobel and Olivier Schoenfelder took the early lead in Gothenburg while Americans Tanith Belbin and Benjamin Agosto - one of the favorites for the title going in - have ground to make up after a rare fall. Delobel and Schoenfelder, the reigning world silver medalists, finished first in the compulsory dance with 40.73 points - two points ahead of Canada's Tessa Virtue and Scott Moir, and more than five points ahead of Belbin and Agosto, who are in fifth place. Russia's Jana Kokhlova and Sergei Novitski are in third after the compulsories while Federica Faiella and Massimo Scali of Italy are fourth. Belbin and Agosto arrived as favorites to win the dance title after European and Grand Prix champions Oksana Domnina and Maxim Shabalin withdrew because of his injury. The Americans had devoted extra time this year to compulsories, considered their weakness, in hopes of starting strong at worlds. "It's just a freak accident. It's never happened in practice," Belbin said. "I'm just really bummed out right now because we were really proud of this dance." The Olympic silver medalists were skating strongly with deep edges to the Argentine tango when Belbin stumbled and fell while performing a rotating turn on one foot, called a twizzle. Falls in compulsories - where every couple skates the same pattern for two rotations around the rink - are extremely rare, and the Argentine tango is considered a relatively simple dance. Schoenfelder and Delobel, however, said the Argentine tango isn't as easy as it might have been when first invented in 1934 - given the speed and intricacy that ice dance has now developed. "We have added more to each step," Delobel said. Belbin and Agosto scored a 35.02, which included a mandatory one point deduction. That's lower than they usually score - they had a 35.89 for the same dance at the Grand Prix final - and they'll need strong showings in the final two events to still have shot at becoming the first Americans to win the gold. But this is not altogether unfamiliar territory for the Americans. "Being behind in the compulsories, unfortunately, is something we are very used to," Agosto said. "So, I mean we're just going to have to do what we always done: We just have to skate a strong (original dance) and free dance. I think the programs we have this year are the strongest we ever had."