Virginia Commonwealth reached the Final Four two years ago and the 22nd-ranked Rams appear poised for another trip deep into the NCAA Tournament this year.
They built a 15-point lead heading into the final 2 minutes before the Hawks put on a charge fueled by four 3-pointers. The last of those brought St. Joseph's within three in the final second.
Virginia Commonwealth will take on Massachusetts in the tournament semifinals on Saturday. The other semifinal will send No. 16 St. Louis against Butler.
Dwayne Evans missed only one shot in scoring 25 points and St. Louis rolled to a 72-55 victory over Charlotte. Butler disposed of LaSalle 69-58.
Evans was 8-of-9 from the field and 9-of-9 from the free-throw line for the game. He had 11 points in the game's first 8 minutes, when the Billikens were building a 19-10 lead.
Cody Ellis, with 13 points, was the only other St. Louis player in double figures. Taking away the hot shooting by Evans, the Billikens (26-6) shot just 27 percent.
Chris Braswell had 20 points and 10 rebounds for Charlotte (21-12).
Butler, which played in the NCAA championship game in both 2010 and 2011, improved to 26-7 with its win over La Salle (21-9). The Bulldogs outscored La Salle 11-2 over a 6-minute span in the second half to take control of the game.
Butler had five players, led by Rotnei Clarke's 14 points, in double figures.
Tyreek Duren had 19 points and Jerrell Wright and Tyrone Garland 14 each for LaSalle, which got only 11 points from the rest of the team.
Massachusetts set up its semifinal meeting with Virginia Commonwealth by holding on for a 79-74 victory over Temple.
The Owls closed within two points with 57 seconds to play, but Terrell Vinson hit a 3-pointer for Massachusetts and Sampson Carter added a free throw to put the game out of reach.
Chaz Williams was perfect in 10 foul shots and scored 28 points to lead Massachusetts (21-10). The Minutemen suffered an 18-point loss to Virginia Commonwealth in their regular-season meeting.