The proceeds were earmarked for the Cleveland Clinic Lou Ruvo Center for Brain Health, which was the overall beneficiary of Saturday's event at the MGM Grand, which marked Ali's 70th birthday.
The auction was a highlight of a star-studded night that included an all-star roster of Vegas celebrities and a rousing version of "Happy Birthday" led by Stevie Wonder. President Obama sent a video message that was played for the crowd.
The Las Vegas Sun said Ali was in attendance but did not speak. Ali, who is afflicted with Parkinson's Disease, was actually born in January.
The Sun said the total proceeds from the event were still being tallied but had topped $20 million in past years.