An inspired performance by American imports Malik Hairston and Omar Cook allowed triple Euroleague winners Emporio Armani Milan to keep alive their dream of winning their first title since 1988 after a 72-66 win at Partizan Belgrade on Thursday.
Needing to win by at least four points to reach the last 16, Milan overcame an 11-point deficit in the third quarter and clinched a berth in the second group stage of the competition.
Shooting guard Hairston scored 18 points, playmaker Cook added 17 and Drew Nicholas had six, including a crucial three-pointer coupled with a free throw.
Milan were one of the four teams to secure a top 16 berth in the final round of matches in the preliminary stage and Hairston said it was down to the team's character.
"We had faith in ourselves all along because you can't ever quit and we now have to mature as a basketball team and play better in the top 16 than we did in the preliminary pool," the 24-year-old told Reuters.
"The atmosphere in the Pionir Arena was incredible, the fans did all they could for their team but we got going when the going got tough and we are delighted."
Cook, who had faced Partizan and their boisterous fans several times when he played for city rivals Red Star and Spanish side Malaga, was also impressed by the noise level.
"I've been here before but it was never like this. We are slowly coming together as a team and learning how to win tight games and what we pulled off tonight was amazing," he said.
Nicholas added: This is one of the toughest away courts in Europe and it's almost impossible to win here so we will head into the top 16 devoid of any pressure but confident that we can progress to the quarter-finals."
The second stage features four groups of four, with the top two advancing to the best-of-five quarter-final series whose winners will qualify for the May 11-13 Final Four in Istanbul.
Six-times Euroleage winners CSKA Moscow completed their perfect preliminary stage record with a 10th win after Serbian point guard Milos Teodosic poured 18 points and compatriot Nenad Krstic scored 14 in a 91-83 win at Unicaja Malaga.
It was only the third perfect regular season record since the turn of the century, as CSKA emulated their own achievement in the 2004-05 season and Barcelona's in 2009-10, when the Spanish outfit won the title.
Rampant CSKA had secured a top 16 berth with four games to spare but kept their foot on the gas pedal, much to the delight of their Lithuanian coach Jonas Kazlauskas.
"I hope our fans enjoyed the game and I am happy with the way we played tonight," he told the competition's official website (www.euroleage.net). "We came out focused on both ends of the court and beat a great team."
In contrast, Panathinaikos coach Zeljko Obradovic was fuming after the holders laboured to a 71-66 home win over unfancied German side Bamberg and finished behind CSKA in their preliminary pool with a 7-3 record.
Although Panathinaikos had little trouble in securing a second-stage berth in an easy group, their unconvincing performances prompted Obradovic to warn the players that some of them were perilously close to being shipped off.
"We need more players who are aware what is needed over here because the door is open to those who are not," said Obradovic, who won five Euroleague titles with Panathinaikos as well as one each with Partizan, Real Madrid and fellow Spaniards Joventut.
"Unfortunately, we have players who don't help the team and I cannot pretend the situation is perfect. Things have to change and all players must be ready to play."
Elsewhere, Bilbao beat Caja Laboral 77-72 and knocked them out of the competition in an all-Spanish dogfight while Turkish side Fenerbahce Ulker also advanced with an 83-76 success at already qualified Bennet Cantu of Italy.
The second group stage starts on Jan. 18.