Nemanja Nedovic scored 39 points and earned eight fouls for Panathinaikos.
Panathinaikos and Olympiakos lost some ground this week in the Euroleague, as their road defeats pulled them further away from the top-eight of the table that leads to the playoffs.
On Tuesday Panathinaikos went down 89-81 at Maccabi Tel Aviv, despite putting up a strong resistance to the hosts, threatening the Giannis Sfairopoulos-coached team with an upset.
However the spectacular showing by Nemanja Nedovic (39 points on the night) was not enough for the Greeks to turn the game on its head after reducing a deficit of 15 points, as no other Panathinaikos player went into double figures.
The Greens are now on a 5-10 record, languishing at the 15th spot of the table.
A day later Olympiakos had a similar fate at Fenerbahce, going down 84-77 in Turkey for its eighth defeat in 15 matches. The Reds are going into Christmas on the 10th spot.
The Greeks had a good start scoring 27 points in the first quarter (27-22), but then got frustrated in attack, with the hosts advancing by 13 (70-57). A Sasha Vezenkov-inspired comeback cut the deficit to just one point (75-74) for Olympiakos, but it could not push any further.
Vezenkov was the top scorer for the Reds with 17 points, with the Piraeus team having two players (Octavius Ellis and Kostas Papanikolaou) coming off injured.