Spaniards Caja Laboral, who were on the brink of an early exit in the preliminary group stage, continued their impressive comeback with a 77-51 rout of Besiktas Istanbul which kept them in the driving seat to advance to the knockout phase.
Barcelona beat holders Olympiakos Piraeus 76-68 in a heavyweight clash to avenge last season's semi-final defeat to the Greeks, CSKA Moscow overpowered Bamberg 90-83 and Real Madrid achieved a thrilling 75-74 victory over Zalgiris Kaunas.
Roth, who joined Maccabi this season after playing for a myriad of less-fancied Israeli teams, averaged 0.9 points and less than five minutes on the court until his moment of glory at home to Fenerbahce.
The 30-year-old journeyman scored eight points, including two three-pointers, and dished out six assists in 15 productive minutes to earn a standing ovation from the jam-packed Nokia Arena.
"I've been dreaming about this since I was five because nothing compares to the lights of this arena," a delighted Roth told the competition's official website (www.euroleague.net).
"I am really happy I could help the team get this very important win. It's our first in the top 16 and now we have to ride the momentum."
Maccabi coach David Blatt, who guided Russia to the 2007 European Championship, said: "We didn't expect Moran to put on such a good show although we knew he was capable of this. Winning by such a big margin is a big bonus for us."
Shooting guard Ricky Hickman picked up 24 points and fellow American centre Shawn James grabbed 22 for Maccabi who have a 1-2 win-loss record while Fenerbahce are rooted to the bottom of their section with three defeats.
The second group stage comprises 16 teams divided into two pools of eight. The top four in each section advance to the best-of-five quarter-final series from where the winners progress to the May 10-12 Final Four in London.
Written off after losing six of their opening seven games, Caja squeezed into the top 16 with three wins in a row and now look unstoppable after registering another three on the trot to go first in their section.
They took an early 21-2 lead against Besiktas and never looked back as shooting guard Brad Oleson recorded 13 points and three other players chipped in with 12 each, providing the kind of team chemistry the Basque outfit were so bereft of earlier in the season.
"We have improved a lot in the last few games," said the 29-year-old Oleson who once plied his trade for lower league Dodge City Legend in the United States after completing his college career at Alaska Fairbanks.
"Nobody on this team stepped back when we were in a difficult situation in the last games of the regular season. The guys took two steps forward and now we need to stay top and not relax."
CSKA made it three wins out of three in the second group stage but not before they were pushed to the limit by Bamberg for the third time this season, the Russians having edged out the plucky Germans in similar fashion in their last two meetings.
Forward Viktor Khryapa led CSKA with 19 points while Serbia playmaker Milos Teodosic and guard Dionte Christmas added 17 each to cancel out a valiant solo effort by Bamberg's Slovenian forward Bostjan Nachbar who amassed 35 including six three-pointers from seven attempts.
"It was a high-quality game and a nice one to watch as both teams played well," said the 31-year-old Nachbar who played for several NBA teams before moving back to Europe in 2008.
Croatian centre Ante Tomic cheered Barcelona with 15 points against Olympiakos in an ill-tempered game littered with technical fouls.
Montenegrin-born forward Nikola Mirotic bagged 17 in a dramatic victory for Real Madrid marred by a post-game scuffle between rival players.
Zalgiris appeared set to stun the winners of a record eight European titles before Sergio Rodriguez buried a three-pointer with three seconds left and a brief altercation followed after Marko Popovic narrowly missed a three-point shot on the buzzer at the other end.
Elsewhere, league top scorer Bobby Brown collected a game-high 20 points in Montepaschi Siena's 82-76 home win over Khimki Moscow and former Los Angeles Lakers guard Jordan Farmar notched 15 in Anadolu Efes Istanbul's 71-62 defeat of Alba Berlin.