The special, which brought back some of the biggest names in the show's history, garnered a 14.2 household rating on NBC versus a 5.5 rating for the All-Star Game on TNT and TBS, according to the 56 markets monitored by Nielsen.
The rating for the SNL show translated into 23.1 million viewers from 8-11:30 p.m. ET. The program was shown on tape delay for the West Coast, which might have turned into a positive for the NBA.
Turner Sports averaged 7.2 million viewers, but the overnight rating was still up 12 percent versus last year's broadcast, the network said.
This year's NBA All-Star Game overnights still beat out the metered ratings for seven of the previous 10 games.
It was a closer battle on Twitter, where 1.3 million tweets were sent out about the SNL special versus 1.1 million on the NBA All-Star Game, according to Nielsen Social.
The SNL show counts as NBC's most watched prime-time entertainment telecast, in total viewers, since May 13, 2004. That night "ER" had 23.9 million viewers on the night of the "Frasier" finale. That number excludes post-Super Bowl programs.
The West beat the East 163-158 in the highest-scoring NBA All-Star Game.
'SNL' Destroys ASG In Ratings
Colin Cowherd discusses "Saturday Night Live" airing the 40th anniversary special on Sunday and why its ratings were so much better than the NBA All-Star Game, which aired at the same time.