The Greens led 47-28 at the break against the already eliminated visitors and coasted to the win with Demos Dikoudis top-scoring with 19 points.
Dimitris Diamantidis added 13 and Milos Vujanic had 11 for the Greens. Every player on Panathinaikos played at least 8 minutes and scored at least 2 points. For Prokom, Rashid Atkins had 15 points and Jasmin Hukic added 12.
Israelis win tough in France
Maccabi Elite Tel Aviv sealed the last quarter-final berth from Group D with a dramatic overtime victory in France.
Tal Burstein was Maccabi's hero, top scoring with 21 points, after the Israeli outfit threw away a 77-65 advantage inside the final six minutes.
Aaron Miles missed a free-throw with two seconds remaining but scored the rebound to level the match although ultimately his efforts ended in vain.
Unicaja set-up Spanish derby
Unicaja reached the last eight by thrashing Dynamo Moscow 73-62 before a sell-out crowd in Malaga and will now have home court advantage against Barcelona in the quarter-finals.
The Russian faces a winner takes all showdown against Benetton next week, with the winner advancing to the playoffs to face Panathinaikos.
Unicaja's hero was Marko Tusek, who came off the bench for 19 points.
Tau march on
Tau Cermaica continued their good form with a 72-77 win at Lottomatica Roma for a seventh home Euroleague win on the bounce. Roma dropped to a record of 1-4 and now have hardly any chance of making the quarter final playoff.
Tiago Splitter scored 18 points for Tau, took 9 rebounds and drew 10 fouls. Mirza Teletovic and Igor Rakocevic added 17 each with Sergi Vidal 10. Ognjen Askrabic took an impressive 19 points and 7 rebounds for Roma, with Dejan Bodiroga 17 and David Hawkins 14.