Nearly 13,000 fans were in attendance at Thompson-Boling Arena in Knoxville.
Summitt, the all-time winningest coach in women's college basketball, became just the sixth college coach to eclipse the 800-win mark, the third in Division I.
"I'm not as old as I seem," said Summitt, who is 50. "Eight-hundred wins is hard for me to believe."
Dean Smith of North Carolina is the all-time leader in college basketball with 879 wins. Kentucky's Adolph Rupp is second with 876.
Summitt has led Tennessee to six national championships, second only to John Wooden's 10, and has a career record of 800-161. All of it has come at Tennessee, where she showed her appreciation Tuesday.
"I want to thank the greatest fans in women's basketball, and that's all of you," she said. "Thank you."
Summitt is three wins ahead of Texas women's Coach Jody Conradt (797-262), but has coached 98 fewer games. Both started the season with 788 victories, but Summitt is ahead in the race for 800 with an 12-3. Conradt is 9-4.
When Summitt won her first game in 1974, a 69-32 victory over Middle Tennessee State, just 53 people attended. A crowd of 12,791 showed up Tuesday.
"It gives you a warm feeling," said senior forward Gwen Jackson, "something you'll never forget."