AMHERST, Mass. (AP) -- No. 19 Massachusetts needed a spark and coach Derek Kellogg knew it was Chaz Williams' time.
Williams scored eight of his 22 points in the closing six minutes Wednesday night, leading the Minutemen to a 66-62 comeback win over Saint Joseph's in the conference openers for both teams.
''He, at times, puts us on his back and makes huge plays,'' Kellogg said. ''He did that again tonight. It wasn't surprising for me. I was like, 'These are going in.' When he misses them, I'm surprised.''
Saint Joseph's had opened a nine-point lead with 6 1/2 minutes left, but Williams nailed a pair of 3s as UMass scored eight of the next 10 points, his second one closing it to 59-56 with 4:28 left.
''Huge. Those are the plays we've become accustomed to from the guy I think is the best player in our conference,'' Kellogg said.
Williams also did an excellent job on Saint Joseph's best 3-point shooter, Langston Galloway, when the Hawks had a chance to tie it in the closing seconds.
''I love a challenge,'' 5-foot-9 point guard said, talking about facing the other team's best player.
Maxie Esho scored 12 points and Raphiael Putney had 11 for the Minutemen (13-1 overall, 1-0 Atlantic-10).
''It was a big-boy game and we weren't big enough,'' Saint Joseph's coach Phil Martelli said, upset by his team's 17 turnovers.
Halil Kanacevic led Saint Joseph's (9-5, 0-1) with 19 points and 13 rebounds. Galloway had 18 points and DeAndre Bembry 16 for the Hawks, who had their five-game winning streak snapped.
''He's a great player. He's great with the ball and makes everyone on the court better,'' Kanacevic said of Williams. ''I think we did a pretty good job on him in the game, honestly, but the turnovers killed us.''
UMass pulled out the win despite an off night by center and second-leading scorer Cady Lalanne, who picked up two early fouls. He finished with four points.
''The will to win in the end was nice, though,'' Kellogg said. ''If you're going to try and do something special, you've got to win some games where you get outrebounded and shoot very poor, I think, from the 3-point line.''
UMass hit only 5 of 15 from beyond the arc, with Williams going 3 of 5.
Kanacevic's basket with just over nine minutes to play broke a 48-all tie and triggered a 9-0 run over a 2:35 stretch. He also scored off a baseline jam, nailed a free three and hit a jump hook in the lane to give the Hawks a 57-48 lead with 6:27 to play.
After Williams brought them back, Saint Joseph's maintained its 3-point lead until he scored off a drive and Esho had a steal from Bembry and breakaway jam, pushing the Minutemen ahead 63-62 with 64 seconds to play.
After a jump ball gave the ball back to UMass, Trey Davis nailed two from the line to make it 65-62 with 33 seconds left.
Papa Ndao missed a 3 with 4 seconds left and Davis sealed it with a free throw.
The Minutemen, who trailed by three at halftime, scored the first seven points after intermission, taking a 35-31 edge on Putney's 3 from the right corner.
The Hawks played sloppily in the opening minutes of the second half, allowing a pair of easy drives to the basket and an alley-oop dunk off an inbounds and combined that with four missed layups on the other end. But they struck with five points in 5 seconds, taking a 42-41 lead on Wilson's breakaway layup with 12:16 to play after Kanacevic nailed a 3 from the top.
The lead then changed hands four times over the ensuing 2 1/2 minutes before Saint Joseph's went on its run.
Lalanne picked up two fouls in the opening five minutes and played just six minutes in the first half.
The Hawks controlled the tempo for the opening seven minutes, slowing it down and pulling to a 16-7 edge on Galloway's jumper from the right corner, but UMass used a full-court press to pick up the pace, forced a handful of turnovers and went on a 16-5 run over the ensuing 6 minutes.
Saint Joseph's then scored 10 of the final 15 points in the half to take a 31-28 edge into intermission.
The Hawks committed 10 turnovers in the opening half. UMass missed eight of nine 3-point attempts.