SAN DIEGO (AP) -- The day started with a bracket-crushing blow. More upsets followed. Four overtime games, a record. A buzzer-beater, a pair of late-night scares.
OK, now breathe.
This was just one day.
There are still 47 games left, 16 of those on Friday.
After one of the wildest opening days in NCAA tournament history, one that cost millions their shot at $1 billion, it's hard to imagine there won't be more chaos to come.
''I've heard this before where there really aren't upsets anymore,'' Harvard coach Tommy Amaker said after the Crimson pulled off one of Thursday's biggest takedowns. ''There may be some surprises, but I just think when you're looking at seeds and if you're playing this time of year, you're probably a pretty good basketball team.''
We'll start with the billion.
Warren Buffett offered the unprecedented prize to anyone who could come up with a perfect bracket.
Forty minutes into the first full day of the tournament, roughly 83 percent of the would-be billionaires were done after Dayton, the No. 11 seed in the South Regional, toppled sixth-seeded Ohio State 60-59 in Buffalo, N.Y.
Just the beginning.
No. 12 East seed Harvard started a how-can-that-be run of games in Spokane, Wash., by knocking off fifth-seeded Cincinnati 60-59.
Two upsets, and almost everyone shooting for perfection was eliminated before they got home from work, the number of blemished brackets up to about 95 percent.
The day of dead pools continued in Spokane, where No. 12 West seed North Dakota outlasted fifth-seeded Oklahoma 80-75.
Thanks for playing everyone. Less than 1 percent of you are still in it.
It was a 9.2 quintillion-to-1 pipe dream to begin with, and Buffett has to like his chances even more after a day like this.
Bracketers in contests by ESPN and CBSSports.com suffered similar fates, leaving less than 1 percent unblemished.
''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.''
And that wasn't it.
Not at a point in the college hoops timeline where upsets, seedings and status have little bearing on the bracket.
The opening day of the 64-team bracket included four overtime games, a record.
Connecticut had the first, beating Saint Joseph's 89-81 in coach Kevin Ollie's NCAA tournament debut. North Dakota's win over Oklahoma came in overtime after Lawrence Alexander hit a 3-pointer with 11 seconds left in regulation.
Saint Louis rallied late to force overtime and beat North Carolina State 83-80 in Orlando, Fla., and San Diego State needed an extra 5 minutes to outlast New Mexico 73-69.
Including Tennessee's win over Iowa in the First Four, that's five overtimes in the opening 20 games.
Now that's madness in March.
''We didn't want to end on that kind of note. We didn't want to bow out of the tournament this early,'' said Saint Louis' Rob Loe, who had 22 points and 15 rebounds. ''We're here to win, and we're here to put our mark on basketball.''
Of course the day included a buzzer-beater.
It came in Milwaukee, where Texas' Cameron Ridley gathered an offensive rebound and put it up just out of the reach of Arizona State's 7-foot-2 center Jordan Bachynski and into the basket, sending the Longhorns to an 87-85 victory over the Sun Devils.
''We were fortunate,'' Texas coach Rick Barnes.
So many weren't, especially those who had hoped to win some coin with a perfect bracket.
With Dayton's opening win, about 83 percent of the brackets in Yahoo's Tourney Pick 'Em game were one and done, perfection flushed in 40 minutes. The wins by Harvard and North Dakota State only figured to add to the number of disappointed billionaires-in-waiting 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 the Bison roamed over the Sooners in the evening, 0.4 percent of the brackets were still perfect.
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 to the 2.2 percent that had the Buckeyes going all the way to the Final Four: Oops!
Through 12 games, there were 41,315 perfect brackets out of the original 11 million - or about 0.3 percent.
This, of course, is nothing new.
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 it may be moving at an even faster pace this year.
AP Sports Writer Jon Krawczynski in Minneapolis contributed to this story.