Fenerbahce Tarfin made a winning start to the new EuroLeague season by beating Virtus Bologna 78-68, while Besiktas fell narrowly to Valencia on their return to the competition after 13 years, and Anadolu Efes let an early lead slip away against Barcelona.
Fenerbahce pulled clear late on Friday to secure a 10-point victory over Virtus, whereas Besiktas came within one possession of completing a comeback before losing 96-94.
A day earlier, Anadolu Efes opened its campaign with an 89-82 defeat in Barcelona.
Fenerbahce established an early advantage against Virtus Bologna and went into halftime narrowly ahead at 39-38 after the Italian side briefly moved in front during the second quarter.
Virtus came out strongly after the break and built a 51-46 lead, but Fenerbahce responded with an 11-2 run to turn the game around and entered the final quarter 59-55 ahead.
The visitors drew level at 60-60, although Fenerbahce quickly regained control and began to pull away in the closing minutes before wrapping up a 78-68 victory.
Talen Horton-Tucker led Fenerbahce with 13 points, while Wade Baldwin added 12. New arrival Braxton Key finished with 11 points and 10 rebounds, recording a double-double.
Marcus Carr scored 12 points for Virtus Bologna.
Besiktas, playing its first EuroLeague game in 13 years, made a fast start against Valencia and moved eight points ahead late in the opening quarter.
Valencia answered with 11 consecutive points, however, and carried a 54-51 lead into halftime before stretching the gap further early in the third quarter.
Besiktas fought its way back into contention in the final period and eventually leveled the score at 86-86. Scottie Wilbekin then hit a 3-pointer to put the Istanbul side 91-86 ahead, but Valencia responded and tied the game again at 94-94.
With Valencia holding a 96-94 advantage in the final seconds, Besiktas received one last opportunity after missed free throws at the other end. Jaylen Nowell's potential game-winning 3-pointer did not fall, allowing the Spanish side to hold on.
T.J. Shorts led Valencia with 26 points, while Nikola Mirotic added 13. Eugene Omoruyi and Nowell scored 17 points each for Besiktas, followed by Conor Morgan with 15 and Wilbekin with 12.
Anadolu Efes had opened the Turkish clubs' EuroLeague campaigns on Thursday by racing into a 17-4 lead against Barcelona and finishing the first quarter 25-16 ahead.
Barcelona gradually cut into the deficit in the second period before moving in front 45-44 at halftime, with Dario Brizuela scoring 13 points during the quarter.
Efes recovered after the break and entered the final period with a 67-63 advantage, but the lead changed hands several times as the game tightened up.
Justin Robinson's late 3-pointer put Barcelona 86-82 ahead with 49 seconds remaining. Efes called a timeout, but Mike James lost possession on the following play, and Barcelona closed out an 89-82 victory.
Brizuela finished with 20 points for Barcelona, and Kevin Punter added 18, while James led Anadolu Efes with a game-high 22 points and Dario Saric contributed 17.
Elsewhere on Thursday, Bayern Munich edged Hapoel Tel Aviv 86-84, Dubai Basketball beat Real Madrid 78-77, Zalgiris Kaunas defeated Crvena Zvezda 83-77, and Panathinaikos overcame Paris Basketball 91-72.
Olympiacos recorded a 106-89 victory over Baskonia, while ASVEL beat Maccabi Tel Aviv 84-74.