Olympiacos registered an 87-83 overtime victory over Panathinaikos on Saturday to double its lead over the Greens in the Greek League. The Reds remained undefeated thanks to a 25-point outburst from Yotam Halperin. The guard, who made 6 of 9 triples, scored the first 5 points of overtime to put Olympiacos ahead for good. The hosts led by double figures early in the fourth quarter before Antonis Fotsis and later Dimitris Diamantidis led Panathinaikos back to a 76-76 tie at the end of regulation. Milos Teodosic and Ioannis Bourousis added 12 points apiece for the winners. Diamantidis had 21 points, 7 rebounds and 7 assists for Panathinaikos and Mike Batiste posted 16 points and 8 rebounds. The Greens dropped to 23-2. PAOK held on to third place with a 66-56 win over Kolossos VAP. Dante Stiggers scored 20 points and Todor Gecevski and Robert Dozier posted double doubles to lead PAOK, which is now 15-10 and has a two-win lead over fourth place Aris BSA. Panionios beat Aris 89-80 as Giorgos Tsiaras shined with 22 points and 8 rebounds and Ryvon Covile had 18 and 11. Kostas Charalampidis scored 20 points for Aris in defeat. In other games, Kavala edged Panellinios 81-84, Maroussi topped AEK 78-69, Ikaros beat Iraklis 73-68 and Ilisiakos routed Peristeri 75-52.