Defending Euroleague champions Panathinaikos dropped their Top 16 to 1-2 after a loss to Montepaschi, while last year's runners-up CSKA Moscow fell to Unicaja.

Montepaschi earned an impressive 84-75 victory over the Greens in Siena to offer their bid to reach the last eight a major boost by lifting their record to 3-0.

The holders, meanwhile, suffered a major setback in their title defence.

Bootsy Thornton led the hosts with 23 points, but it was the Montepaschi defence that proved crucial as the Italians forced 20 turnovers.

Meanwhile in Spain, Unicaja clawed their way into contention for one of the quarter-final spots in the toughest group after beating 2006 champions and 2007 runners-up CSKA Moscow 72-67.

The Malaga club improve to 1-2 while the Russian champions fall to 2-1 and lose their first Top 16 game since their title-winning run in 2006.

Daniel Santiago led all scorers with 20 points and added six rebounds for the hosts.

Olympiacos needed overtime to earn their first win of the Top 16 season, beating Zalgiris Kaunas 86-84 in Piraeus, Greece as both teams are now 1-2.

In a dramatic finish to the fourth period Damir Markota hit a three-pointer to give the visitors a three-point lead with one minute to go, but Lynn Greer matched him on Olympiacos' next possession.

Greer led all scorers with 22 points, while Marc Jackson added 21 points and 11 rebounds and Qyntel Woods scored 18 points, including the game-winning free throws with 5.8 seconds remaining.

Marko Popovic missed a possible game-winning three-pointer at the end of the extra period to close out the match.

Jeremy Stahl / Eurosport