Panathinaikos successfully fended off a strong challenge by Partizan Belgrade last night at the Serbian host’s sold-out Pionir Arena to win 73-65 and remain the Euroleague’s only undefeated club after six rounds of group play. Panathinaikos is now two games clear in Group B. For Partizan, with three wins and three losses, last night’s defeat was the team’s first setback at home in this season’s Euroleague. «Partizan is playing very well this season and it would not have been a surprise had they beaten us in the end,» said Panathinaikos coach Zeljko Obradovic, a former player and coach at the Belgrade club. «Thanks to the Partizan fans for their warm welcome to me. It was very emotional,» added Obradovic, who attributed his team’s sixth successive win to crucial defensive play in the final minutes of play. Mike Batiste led Panathinaikos with 15 points. Dimitris Diamantidis and Nikos Hatzivrettas added 12 points apiece.