The Greek side joined compatriots Olympiakos Piraues, 2010 champions Barcelona and six-time winners CSKA Moscow who qualified last week for the season-ending tournament from May 11-13 in Istanbul.
The showcase event in the Sinan Erdem Dome, the venue of the 2010 world championship, could produce the first all-Greek final as CSKA take on Panathinaikos and Barcelona clash with 1997 winners Olympiakos.
Having clawed their way back into the series by edging out Maccabi in Game 4, Panathinaikos came out on top in the enthralling tie-breaker in front of 18,000 fervent home fans in the OAKA Arena.
Greece playmaker Dimitris Diamantidis was instrumental in their success with a game-high 25 points, including a decisive free throw with five seconds remaining.
Former Maccabi guard Sarunas Jasikevicius, who won back-to-back Euroleague titles with the Israeli club in 2004 and 2005, added 13 points and three assists with a mature performance worthy of his illustrious career.
The 36-year-old Lithuanian, who also had spells with NBA outfits Indiana Pacers and Golden State Warriors, hit several key shots as Maccabi threatened to swing the match their way with a 12-0 run early in the second half.
Panathinaikos replied with a 10-0 rally much to the delight of their Serbian coach Zeljko Obradovic, who has won a record eight Euroleague titles with four different clubs including five at the helm of the Greek champions.
But Maccabi, who trailed by as many as 10 points in the final quarter, refused to lie down and almost forced overtime as Guy Pnini tied the score before Diamantidis sank one of two shots from the foul line.
The visitors had the final possession but came nowhere near a shooting position as a cluster of Panathiniakos players formed a wall in mid-court and forced a turnover.
They embraced each other as jubilant home fans lit flares on the buzzer which signalled the end of a rip-roaring contest between two of Europe's most heralded basketball giants.