SAN DIEGO » So you were confident in your bracket, hoping to win the office pool, maybe get lucky and take down that $1 billion prize Warren Buffett is offering for a perfect run of picks.

One game in and … done.

Way to go, Dayton.

And thanks for piling on, Harvard.

The first full day of the NCAA tournament got off to what has become its usual scream-at-the-TV start, opening with two first-afternoon upsets that sent a wave of crumpled brackets — about 95 percent of them missed at least one of the first eight games — flying from Buffalo to San Diego.

"Being bounced from the billion THAT early definitely made me feel some type of way," said Marcus Arman of Portland, Ore. "I can tell you this: I will not be supporting the city of Dayton in any shape, form or fashion so long as my foam finger still points upward."

Dayton, the No. 11 seed in the South Regional, got it started in the first game Thursday, knocking off sixth-seeded Ohio State 60-59 in Buffalo, N.Y.

A few hours later, No. 12 East seed Harvard had its David-vs-Goliath thing working for the second straight year, taking down seventh-seeded Cincinnati 61-57 in Spokane, Wash.

Thanks for playing everyone. Those two upsets, both of which ended before most people got home from work, eliminated almost everyone shooting for perfection.

With Dayton’s win, about 83 percent of the brackets in Yahoo’s Tourney Pick ‘Em game were one and done, perfection flushed in 40 minutes. Harvard’s win — along with the small group who didn’t pick Wisconsin or Pittsburgh — only figured to add to the number of disappointed would-be billionaires once the official numbers were released.

"Yesssssssssss HARVARD!!!!!!! Messing up a lot of peoples chances at $1 billion lol," former Harvard and current Houston Rockets guard Jeremy Lin said on Twitter.

At CBSSports.com, Dayton took out 81 percent of the poolers in the bracket challenge. By the time Harvard won, just 5 percent of the brackets were still perfect.

It was a 9.2 quintillion-to-1 pipe dream to begin with, and Buffett has to like his chances even more now.

Of the 11 million brackets in ESPN’s Tournament Challenge, over 80 percent had Ohio State advancing to the next round. That’s about 8.8 million brackets with a blemish after one game.

And 2.2 percent had Ohio State going all the way to the Final Four: Oops!

After the first afternoon of games, just 5.7 percent of ESPN brackets had a chance at perfection.

This, of course, is nothing new.

We are in the era of upsets, where seedings and status have little bearing on the bracket.

A year ago, not a single person of the 11 million who entered on ESPN’s website was perfect after a first day filled with upsets. Just four got 15 out of 16 right.

By now, we’ve learned that Cinderella’s carriage doesn’t turn into a pumpkin once the NCAA tournament starts. It becomes a Formula One car racing through the bracket — and is doing it again this year.

AP Sports Writer Jon Krawczynski in Minneapolis contributed to this story.