Chaz Williams is as quick as a hummingbird — and he’s not much bigger than one, either.

The UMass star, who is listed at 5-9 but looks more like 5-6, was the catalyst during a second-half surge in a 76-66 victory over Dayton on Saturday. And in a battle of two preseason first-team All-Atlantic 10 point guards, he won his duel with UD’s Kevin Dillard.

“When I’m playing against great point guards like Dillard, I try to focus on the defensive side of the ball,” Williams said. “I’m not going to take that many shots. When I do that, I try to be a run-the-show point guard and find my teammates and just play like that. I think I did a pretty good job on him today.”

Williams had nine points, nine assists and four turnovers in 33 minutes, while Dillard had eight points, six assists and two turnovers in 34 minutes.

Dillard helped UD take a 54-51 lead on an 11-0 run, capped by his 18-footer with 11:12 left. But during a four-minute scoreless stretch for the Flyers after that, the senior committed both of his turnovers and had a drive blocked as UMass took control.

“I looked at him, and the bottom line with him is I think he got fatigued,” said UD coach Archie Miller, who pulled him briefly with just under five minutes to go. “I thought he played too many minutes in the first half. I did not give him a blow. That’s on me.

“I thought the wear and tear of his legs and decision-making hurt us. He goes through those stretches where he tries to make plays and tries to win, which all great players do. He needed a blow.”

The Flyers have just two healthy scholarship guards, and Miller’s only other backcourt option is walk-on Brian Vonderhaar.

Up and down: Trailing by six at halftime, the Flyers scored the first six points of the second half to tie it up. The teams traded baskets at a furious pace over the next 90 seconds — each getting six points in that span.

UMass then ripped off eight points in a row, including two ally-oop dunks off nifty passes from Williams, the A-10 assist leader.

But UD charged back. Tied at 60, Dyshawn Pierre looked as if he made an inside bucket, but teammate Jalen Robinson was called for offensive goaltending.

Williams then scored on a drive and assisted on another for a four-point lead with 4:40 to go. A pair of 3-pointers by Terrell Vinson 40 seconds apart made it a nine-point game with 1:10 left.

UD is in 13th place in the A-10 and needs to get into the top 12 to qualify for the conference tournament.

“To me, there’s urgency every day,” Miller said. “Our guys didn’t spend the last week after we had maybe our best performance of the season (against Xavier) and said, ‘Boy, we’re in good shape.’ Our guys prepared hard this week. We also were playing a very talented team at home that was coming off three (losses). They were ready to play, too.

“We were right there. … Today was just another example of not being unable to get something done in the fundamentals of basketball. If it’s not turning it over, we’re not rebounding. If we’re rebounding, we’re turning it over. We’re not able to put all facets of the game together.”

Rebounding hurt: The Minutemen were 10th in the A-10 in rebounding margin at plus-0.2 per game, while the Flyers were fourth at plus-4.4. But UMass had a 36-27 edge on the boards and scored 15 second-chance points.

Milled burned a timeout when the Flyers fell behind, 20-14, with UMass having scored three buckets on put-backs.

Streak ends: Dillard was 33-of-33 on free throws in the last two minutes of games until missing the second of a 1-and-1 with 1:45 left.