After Arizona’s five public appearances at McKale Center this fall, it’s pretty clear that Allonzo Trier can put up crazy offensive numbers, and that Deandre Ayton can throw together double-doubles without too much trouble.

The surprise was that No. 3-ranked Arizona needed both of those things to happen before the Wildcats could breathe easy in a 103-78 win over UMBC on Sunday at McKale Center.

In what was technically an add-on game to the Battle 4 Atlantis tournament in the Bahamas that UA will play in next week, the Retrievers of the low-major America East Conference scrambled into McKale after giving SMU a scare on Friday in their season opener.

Just 25 seconds after tipoff, UMBC guard Jarius Lyles hit a 3-pointer, as if to announce that the Retrievers planned to stick around in this one, too. Certainly, Lyles did: The graduate student scored 31 points on 10-for-21 shooting while collecting five rebounds, four assists and three steals.

Lyles’ scoring, plus UMBC’s 50-percent shooting from 3-point range and a little zone defense, made things interesting for much of the fast-paced game. So much so that, when Jourdan Grant hit a 3-pointer in the right corner two minutes into the second half, the Retrievers had cut UA’s lead to just 58-55 and prompted coach Sean Miller to call timeout.

“There are times when we broke down, but there are times when sometimes you have to give credit to the opponent,” Miller said. “They tested us. It was a really good game for our team to learn and grow. ... It’s up to us to work on a few things I think we can control better defensively.”

One of which is likely 3-point defense. UMBC — formally known as the University of Maryland, Baltimore County — hit 14 of 28 3-pointers, with five different players making at least two each (Lyles, not surprisingly, had five).

Ayton said the Retrievers made some tough shots but said it was “different for me” to have to guard big players on the perimeter. Brandon Horvath, a 6-foot-9-inch forward, made 2 of 3 from beyond the arc.

“They spread us out,” guard Parker Jackson-Cartwright said. “Their bigs are like guards. They can make shots and put it on the floor and No. 10 (Lyles) led the charge. He was terrific all night.”

The former guard at Maryland’s powerhouse DeMatha High School, who also played a season at VCU is, essentially, the kind of top-shelf guard Arizona might expect to find from a Pac-12 or other high-major team. He surprisingly stayed at UMBC even as he could have become immediately eligible in a higher-level conference this season as a grad transfer.

“He’s a grad student who had options to go other places and he decided to stay with UMBC,” Retrievers coach Ryan Odom said. “It means a lot for him to finish up with his teammates, his family and coaches nearby.”

In a way, Arizona was glad Lyles stuck around, too. Having to face Lyles and UMBC’s shooters, and deal with some defensive roadblocks was exactly the kind of warm-up they may have needed after facing two exhibition opponents and a lesser-talented NAU team on Friday.

“They’re a great team. They have older players and a good coach,” Jackson-Cartwright said. “They ran a lot of good action and they switched their defenses. They kept us honest all night and made it tough on us. But we just tried to withstand all their runs.”

UA did just that, while having some fun along the way. Arizona had no trouble playing along with the Retrievers fast pace, scoring 25 fast-break points to UMBC’s 11, while also dominating inside with some flash.

Ira Lee threw down a forceful dunk and picked up a foul early in the second half, hitting the and-one, just after UMBC had cut it to three points.

Ayton put on a show in both halves. Freshman guard Alex Barcello fed Ayton for an alley-oop midway through the first half while Ayton put an exclamation point on the win with 2:35 left in the game, when he grabbed a missed corner shot from Emmanuel Akot, then threw it in all in one motion as he bent around the bucket.

It was not your everyday offensive rebound.

“I heard coach Miller say ‘Deandre, go get that one,’” Ayton said, “and I just dunked it.”

Told about Ayton’s remark, Miller cracked a smile.

“I’ll take full credit for that dunk,” Miller said. “If that’s what he believes, great. There aren’t many players who can go do what he did.”

Then there was Trier, who poured in 15 points in each half, going 5 of 12 from 3-point range and making 10 of 18 shots overall.

In two games so far this season, Trier is averaging 31.0 points, while shooting 61 percent from the field and making half of his 20 3-point attempts. He also became only the eighth player in Arizona basketball history to hit the 30-point mark in consecutive games (Only Jerryd Bayless, in 2007-08, has done it three times in a row).

All that is a product of skill and work ethic, the way Miller describes it, but also a function of the talent around Trier.

“Allonzo is very efficient with how he’s playing the game right now,” Miller said. “But you also have to credit his teammates. It’s not easy to just load up on him. He has a very fast, unselfish point guard in Parker who understands how to play the game. He’s surrounded by a lot of weapons.

“We have an inside game that sometimes teams have to double-team. Deandre is an excellent passer and Dusan (Ristic) is a willing passer as well. So it’s set up for him, as long as he continues to play the game this way, where he’s taking good shots.”

Trier’s supporting cast expanded even more Sunday, too.

After using only a seven-man rotation in a 101-67 win over NAU in Friday’s opener, the Wildcats welcomed back forward Keanu Pinder from a one-game suspension (NCAA rules), Dylan Smith from a three-game suspension (team rules) and wing Brandon Randolph (concussion) though Miller was again with only one full-time assistant coach, Lorenzo Romar, after Mark Phelps was suspended for a second game (NCAA rules) and Book Richardson is suspended without pay after being arrested on federal bribery and fraud charges.

Miller played Randolph only two minutes in each half, noting that the freshman had only been cleared for full contact on Saturday after suffering a Nov. 3 concussion, while Pinder had four points, four rebounds, two steals and a block in 12 minutes off the bench. Smith hit 2 of 4 3-pointers in what was his debut as an Arizona player after transferring from UNC Asheville in 2016 and sitting out last season.

All the extra help is returning to the Wildcats just in time. UA has only one more game remaining before opening play against NC State in the Battle 4 Atlantis on Nov. 22, and that next game is Thursday against Bakersfield — a team that rattled off 17 straight points against the Wildcats at McKale Center last season and lost by only 12.

Miller said Bakersfield is gritty and tough-minded again this season, meaning the Roadrunners should be able to give UA another kind of test it needs.

“Playing three games in three nights (in the Bahamas) really challenges your depth,” Miller said. “We’re not there yet but … my hope is between our practices and that next game that we can be the most ready we can be for a tournament like that.”

Sportswriter for the Arizona Daily Star covering Arizona Wildcats basketball