Pac-12 herd is thinned in a hurry as five of its seven teams lose in first round of NCAA tournament

Say this for the Pac-12 Conference, things can’t get much worse from here on in the NCAA tournament.

The Pac-12 was all proud of its quality depth this season, and then a record seven of its teams were selected for the tournament, tied for most of any conference. If that caused pause in areas east, the Pac-12 privately had to be all giddy.

Then the games began.

And down they started to fall, until by the first round’s end the Pac-12 was staring blankly at a 2-5 record.

Now only Oregon and Utah remain to carry the conference banner, and neither is exactly a lock to advance to the Sweet 16.

Utah, the No. 3 seed in the Midwest, has to meet Gonzaga in the second round. The Bulldogs stirred echoes of top Gonzaga teams of the past in a 68-52 upset of Seton Hall on Thursday. Oregon, considered by many the weakest of the No. 1 seeds, had an easy time with Holy Cross on Friday, but could have a challenging second game when it meets St. Joseph’s.

All seven Pac-12 teams were seeded higher than their opponents, but perhaps tellingly, many still weren’t betting favorites. That conference respect had not been earned everywhere.

Providence was favored over USC, the Friars needing a stretch collapse by the Trojans to win by one. No. 9 Connecticut was favored over No. 8 Colorado and No. 10 Virginia Commonwealth was favored over No. 7 Oregon State. Bettors were so impressed by Wichita State’s play-in victory over Vanderbilt that by the time its game started against No. 6 Arizona, the matchup had fallen to pick-’em status.

No. 4 California, a No. 4 seed in the South, was favored to handle Hawaii, but then point guard Tyrone Wallace broke his hand in practice. For all their supposed talent, the Bears weren’t good enough to hold off the Rainbow Warriors.

This is where the annual reminder arrives: The conference hasn’t won a national championship since Arizona in 1997.

The tournament’s first round brought its usual assortment of upsets, but some were so stunning that before play had even ended Friday, the perfect bracket had become extinct.

ESPN, Yahoo, CBS Sports, the NCAA — none of the online sites had a single perfect bracket remaining in their individual tournament challenges. ESPN said it had approximately 13 million enter its tournament contest.

The biggest upset was easily No. 15 Middle Tennessee State’s 90-81 victory over No. 2 Michigan State. That left the canonization of Spartans Coach Tom Izzo on hold, Magic Johnson completely quiet on Twitter and most of the country wondering — what’s a Middle Tennessee State?

Quick answer: It’s in Murfreesboro, Tenn., site of the bloody Battle of Stones River during the Civil War and about 30 miles south of Nashville. The university actually has the largest undergraduate population in the state (22,000). It owns two NCAA championships (golf in 1965 and tennis doubles in 2007).

Many thought Michigan State was fleeced when it failed to receive a No. 1 seed and Virginia and Oregon did. The Spartans were still viewed a title favorite, but they never led against the unheralded Blue Raiders.

It was the eighth time a No. 15 seed had won, but this was arguably the tournament’s biggest upset in history. It certainly was for Izzo.

“I can’t ever remember one that hurts as bad as this,” he said. “I’ll get over it, I’m a big boy. But it ain’t going to happen today or tomorrow.”

By the time No. 14 Stephen F. Austin upset No. 3 West Virginia with a surprisingly easy 70-56 win in the East, brackets were being tossed into wastebaskets all over the country.

Parity was the theme in college basketball this season, and by the end of the first round teams seeded second, third, fourth, fifth and sixth had all lost.

If nothing else, plenty of intrigue should remain. There should be several competitive and interesting games over the weekend. Kentucky and Indiana meet in a battle of No. 4 and No. 5 in the East. In the West, Yale, an upset winner over No. 5 Baylor, meets a Duke team that has looked vulnerable. And no doubt Wichita State has No. 3 Miami’s attention in the South.

Meanwhile, the Pac-12 looks to its survivors, Oregon and Utah.

sports@latimes.com