DAYTON, Ohio - Saint Joseph's had its perfect season ruined on the same court it pulled off one of college basketball's biggest upsets 23 years ago.

Unranked Xavier shot 71.1 percent from the field and never trailed in ending the Hawks' one-week reign at No. 1 with an 87-67 victory in an Atlantic-10 quarterfinal Thursday.

"It's like I told Coach (Phil) Martelli after the game," Xavier coach Thad Matta said. "We couldn't have played any better than we did today."

Even the Saint Joseph's coach could appreciate how thoroughly his team was dismantled.

"It's stating the obvious, but the better team won today," Martelli said. "They were hungry and desperate. Their three seniors did what seniors do in the darkest of times. ... If you could step back and watch, you'd almost have to admire it."

In the second round of the 1981 NCAA tournament, Saint Joseph's stunned No. 1-ranked DePaul 49-48 on John Smith's late basket at University of Dayton arena.

This time around, the Hawks came in with a 27-0 record and were three victories from becoming the first team since 1991 to enter the NCAA tournament undefeated. But they trailed Xavier by as many as 37 points, and the upset raised questions about how serious a contender the tiny Philadelphia school will be for the national championship.

The rout also tarnished a magical run by a team that was one of the biggest surprises in sports this year, and it could cost Saint Joseph's a top seeding in the NCAAs - although Martelli disagreed.

"The committee will do us right because of our body of work," Martelli said. "Not 40 minutes."

It was the worst loss ever by a No. 1 team against an unranked opponent, and equaled the seventh-biggest loss by a top-ranked team against anyone. A partisan crowd - Xavier is less than an hour away from the arena - began rubbing it in midway through the second half, chanting "Sloppy Joe's!"

Romain Sato led Xavier with 24 points and 11 rebounds, Lionel Chalmers scored 23, and Anthony Myles had 19.

Saint Joseph's backcourt stars Jameer Nelson and Delonte West were held to a combined 11-for-35 shooting, and scored 16 points each. Along with hitting 32 of 45 shots from the field, Xavier (21-10) also held Saint Joseph's to 35.4 percent - its worst performance this season.

"Any loss is devastating, especially when you work so hard," Nelson said. "We take pride in our defense and we let ourselves down with our defense today."

Saint Joseph's, which took over the top ranking spot in the AP poll Monday after Stanford's loss to Washington, was limited to one field goal during a stretch of more than 10 minutes. And the Hawks' biggest weakness, their inside game, was exposed by the Musketeers, who outrebounded Saint Joseph's 43-18.

Xavier, which was ahead 74-37 with 7:56 remaining, has won 11 of its last 12.

"I think we're pretty good," Chalmers said. "We've come a long way since early on. Right now, we're clearly one of the hottest teams in the country."

The Musketeers - who lost at home to the Hawks 81-73 in January with Nelson and West combining for 61 points - scored nearly at will from the start, with Sato and Chalmers slashing to the basket.

Nelson had his worst game of the season, going just 7-for-21 from the field, including 1-for-8 on 3-pointers. By contrast, Chalmers, Sato and Myles were 25-for-34.

"We tried to make it tough for Jameer and West," Sato said. "The last time we played them, they made everything."

Xavier will face George Washington in the semifinals. The Musketeers all but secured an NCAA berth, regardless of what happens the rest of the week.

"Going 3-1 against the Top 25 - not a lot of teams can say that," Matta said. "I believe we are one of the top 64 teams in the country."

George Washington (18-10) trailed early until going on a 17-3 tear in a 79-50 win over Rhode Island. Carl Elliott and T.J. Thompson each scored 14 points for the Colonials, who split two regular-season meetings with Xavier.

Dawan Robinson, the leading scorer for Rhode Island (19-13), played only four minutes with a severely bruised back which he sustained in the first round.

In the other semifinal, host Dayton (23-7) will take on Richmond (20-11).

Dayton (23-7) scored its final 12 points on free throws over the last four minutes to hold off Duquesne 69-56. Keith Waleskowski led the Flyers with 16 points and 10 rebounds.

Jimmy Tricco scored 16 points for Duquesne (12-17).

Temple (15-13) managed only one field goal for a span of 131/2 minutes of the second half of a 64-49 loss to Richmond in the nightcap.

Mike Skrocki's 18 points led the Spiders, while conference scoring leader David Hawkins had 20 for Temple.

AP-ES-03-12-04 0403EST