Updated

TUCSON, Ariz. -- The Arizona Wildcats, with the help of a preseason All-American and an impact newcomer, are putting up a lot of points.

Third-ranked Arizona scored over 100 points for the second straight contest, the first time the Wildcats have done so in the first two games of a season since 2002.

Allonzo Trier scored 30 points, freshman big man Deandre Ayton added 19 and 13 rebounds and Arizona overpowered Maryland-Baltimore County for a 103-78 win on Sunday.

"It's set up for him as long as he continues to play the game this way, where he's taking good shots," Arizona coach Sean Miller said. "No player that I've ever had and seen has worked harder on the game than Allonzo has."

Arizona (2-0) pulled away with Trier's 3-pointer, one of five for the junior guard, for an 86-68 lead, then freshman Alex Barcello drilled back-to-back 3s to put the game away.

The Wildcats made 61 percent of their shots for the game and 15 of 28 3s. Ayton, who had 19 points and 12 rebounds in the opener against Northern Arizona on Friday, made an impact at both ends with dunks and blocked shots.

"Coach loves his big men to run a lot, and I love running the floor," the 7-1 Ayton said. "It's quick baskets.

Guard Jairus Lyles scored 23 of his 31 points in the first half for the Retrievers (0-2). Jourdan Grant added 14.

Maryland-Baltimore County cut the lead to 58-55 early in the second half on Grant's baseline 3, prompting an Arizona timeout. But the Wildcats built their lead back into double digits thanks to a four-minute scoring drought for the Retrievers.

The Wildcats made 21 of 30 first half shots (70 percent). Trier, coming off a career high 32-point night on Friday, scored 15 in the first half.

Still the Wildcats couldn't pull away completely from the Retrievers before halftime, despite making 9 of 14 3-pointers, including three from guard Parker Jackson-Cartwright. Lyles made all four of this 3-point attempts, Maryland-Baltimore Country made eight as a team and shot 53 percent from the floor trying to keep up with Arizona's tempo.

"He's a grad student that had options to go to other places and decided to stay with UMBC," coach Ryan Odom said of Lyles. "It means a lot for him to finish up with his teammates, family and coaches nearby."

Arizona went on a 14-0 run early in the half to take an eight-point lead, and went up 34-18 on guard Dylan Smith's 3 at the 9:46 mark. The Wildcats led 56-47 at the break.

The Retrievers cooled off in the second half and were outscored in the paint 40-18 for the game.

BIG PICTURE

UMBC: The Retrievers were the third-most improved Division I team in the nation, going from seven wins in 2015-16 to 21 last season. Their non-conference season includes a showdown with in-state rival Maryland in late December, which will be on national television.

ARIZONA: The Wildcats have one more game at home before embarking on a trip to the Bahamas for the Battle 4 Atlantis tournament, which will be their first big test of the season. Novembers are typically good for Arizona, as the Wildcats are 44-7 in the month under Miller.

SUSPENSIONS LIFTED

The Wildcats got two players back from suspension. Forward Keanu Pinder and Smith, who missed Friday's opener due to unspecified team rules violations, came off the bench.

"I'm happy for Dylan," Miller said. "Dylan has really done an excellent job academically. It's not easy when you play basketball your whole life, to sit out and not be able to play in the games."

Assistant coach Mark Phelps served the second of a two-game suspension for violating NCAA rules. Also, guard Brandon Randolph saw his first action of the season after passing a concussion test and being cleared to play.

LOVE FOR LYLES

The Wildcats came away impressed with Lyles, who added five rebounds, four assists and three steals to his 31 points.

"Lyles is a heck of a player. You come into McKale Center and get 31, 23 in the first half, you're really, really good," Miller said.

"He was terrific all night, he made his teammates better," Jackson-Cartwright said. "It was a really good test for our team and for myself."

HIGHLIGHT REEL

Ayton brought the crowd to its feet when he grabbed a missed a shot with one hand and dunked with 2:35 to play.

"I heard Coach Miller say 'Deandre, go get that one. I was like, OK,' " Ayton said.

"I'll take full credit for that dunk," Miller said. "That's what he believes, great."

UP NEXT

Arizona: Hosts Cal State-Bakersfield Thursday.