"It was a special night," he said.
The Spartans (14-4, 6-1 Big Ten) stayed in sole possession of first place in the Big Ten and bounced back from a 71-42 loss at Purdue.
Winston connected with Tillman to give him four assists in the game and 817 in his career. Former Spartan Mateen Cleaves, who attended the game, ended his national championship-winning career with 816 assists in 2000 and was happy to have his mark surpassed by Winston.
"He's so selfless and he puts everybody first," Cleaves said. "When you have that mindset, good things always happen. Trust me, I am totally happy turning over the keys to Cassius. I think it's fantastic.
"Here, we're family. I'm Cassius' biggest fan."
Winston knew Cleaves was pulling for him to have the record.
"A lot of times in these situations, you probably want that forever," Winston said. "But it was never like that. He was rooting for me the whole time."
Cleaves presented Winston, a senior, with a ceremonial ball for his achievement after the game.
"Hopefully it'll last for another 20!" Winston said.
The Associated Press contributed to this report.