Holders Olympiakos Piraeus fought back to beat Spaniards Unicaja Malaga 69-61 at home, Real Madrid celebrated an 83-63 win at Zalgiris Kaunas and Russians Lokomotiv Krasnodar edged Red Star Belgrade 87-84 in front of 20,000 passionate Serbian fans.
Bayern languished in the lower tiers of German basketball for three and a half decades before returning to the top flight in 2011 and on Friday they romped to a 94-73 success at Polish rivals Stelmet Zielona Gora.
"The first quarter was very nice but the second was just fantastic," Bayern's Serbian coach Svetislav Pesic, who guided the former Yugoslavia to the 2001 European championship and the 2002 world title, told the competition's website (www.euroleague.net).
"Although we had some poor moments in the game we always responded and that allowed my players to feel comfortable," he said.
No Turkish club has ever won the Euroleague but heavy investment and an influx of quality signings has put the competition's Istanbul trio to the fore for berths in the 24-team competition's knockout rounds if their promising start is anything to go by.
Fenerbahce, who signed Lithuania's former NBA forward Linas Kleiza and trophy-laden Serbian coach Zeljko Obradovic, staged an impressive fourth-quarter comeback to win 102-84 at debutants Budivelnik Kiev on the back of 21 points from Croatian Bojan Bogdanovic.
Their bitter foes Galatasaray were just as clinical in an 84-75 away defeat of Italians Montepaschi Siena, hitting 12 three-pointers from 22 attempts as Puerto Rican playmaker Carlos Arroyo nailed a game-high 21 points and Jamont Gordon added 18.
Anadolu Efes Istanbul eased to an 87-67 home rout of Emporio Armani Milan thanks to 22 points apiece by Serbian forward Dusko Savanovic and American Scotty Hopson.
There was no joy for Serb teams though as Barcelona overpowered Partizan Belgrade 67-60 in a physical battle and Lokomotiv came out on top against Red Star in the cauldron of the Kombank Arena.
"All credit to my players because it's not easy to beat this Red Star team in front of 20,000 people and this is a big success for us because it's our first Euroleague win ever," Lokomotiv coach Evgeny Pashutin said.
Elsewhere, shooting guard Renaldas Seibutis sank a mid-range jump shot with five seconds left to give Lietuvos Rytas an epic 84-83 home win over six-time champions Panathinaikos, topping the scoring with 19 points as Darius Songaila chipped in with 13 and eight rebounds.
CSKA Moscow scraped a 62-59 win at French side Nanterre after trailing by seven points at halftime and Olympiakos also erased an early deficit to beat Unicaja.
Playmaker Vassilis Spanoulis, who engineered back-to-back titles in 2012 and last season, was instrumental for Olympiakos, scoring 13 points in a low-scoring contest and American Pete Petway added as many in front of raucous home support.