Marco Silva's team, who are also going strong in Europe after winning their third straight Champions League group game against Dinamo Zagreb in midweek, went ahead through Luka Milivojevic's powerful 20th minute strike before Ideye Brown sealed the three points in the 61st minute.
The victory leaves Olympiakos on a perfect 30 points, eight points clear of Panathinaikos, who were 2-1 winners at Atromitos on Saturday.
The Greens, who appointed Italian Andrea Stramaccioni as their new coach on Sunday, fell behind to Stefano Napoleoni's 51st-minute opener but fought back to take the points thanks to goals from strikers Nikos Karelis and Marcus Berg.
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The 39-year-old former Inter and Udinese coach Stramaccioni has penned a two-year deal with the Athens giants to take over from Giannis Anastasiou, who parted company with the team by mutual consent last Monday.
Stramaccioni faces a baptism of fire in his first game in charge of Panathinaikos with the small matter of a derby against fierce Athens rivals Olympiakos after the international break on Nov. 21.
The pressure on PAOK Salonika coach Igor Tudor continues to build following the latest setback, a 3-3 home draw with strugglers Panthrakikos.
PAOK wasted a hatful of chances and were let down by defensive errors, the result leaving them well off the pace in sixth place, 15 points behind Olympiakos.
(Editing by Ian Chadband)
