That was close.
The Wildcats improve to 17-2 overall and 6-0 in Pac-12 play, while the Trojans fall to 16-4 overall and 3-4 in the Pac-12.
Markkanen sank five 3s on the night including a deep, desperation 3 off the glass to put Arizona up 70-64 with 33 seconds left, serving as the death blow to USC’s late comeback attempt.
Arizona led by 10 at halftime and took a 22-point lead with 11 minutes left after two free throws by Kadeem Allen but, as it’s happened several times this season, the Wildcats had difficulty closing the game out.
The Trojans strung together a 13-2 run to make it a 58-47 game with under six minutes to play.
The Wildcats missed nine shots in a row at one point and USC continued to chip away at Arizona’s lead.
An and-one by Chimezie Metu trimmed USC’s deficit to 60-52 with 4:47 left, then, after trading baskets, Elijah Stewart converted an and-one of his own to make it a 64-57 with 3:35 left to play.
Later, Alkins fouled De’Anthony Melton at the 3-point line, and Melton converted all three free throws, making it 65-60 with 2 1⁄2 minutes to play.
A long 3 by Kobi Simmons as the shot clock expired was off the mark on Arizona’s next possession, but the Wildcats forced a turnover on USC’s subsequent possession which led to a basket underneath for Markkanen to push Arizona’s lead back to 67-60.
However, the Trojans’ push continued and four made free throws by Shaqquan Aaron made it a 67-64 game with 1:03 left to play.
Markkanen’s 3 made it 70-64, but McLaughlin quickly responded with a layup to make it 70-66.
With under 30 seconds to play, the Trojans were forced to foul and Dusan Ristic split a pair to make it 71-66 with 25 seconds to play.
USC’s ensuing attempts came up short and the Wildcats escaped with the road victory.
Arizona outscored USC 29-19 in the first half, but the Trojans won the second half 47-44.
The Wildcats shot 40 percent from the field and 10-26 from the 3. Meanwhile, the Trojans — whose offense was abysmal at the start — wound up shooting 37 percent from the field and 7 of 21 from 3.
Stewart led the Trojans with a 20-point effort, while McLaughlin and Metu added 14 and 11, respectively.
The Wildcats used an early 3-point barrage to jump ahead to an 11-6 lead with 14:28 to go in the first half. Against USC’s 2-3 zone, Alkins hit two corner 3s while Markkanen added another.
UA head coach Sean Miller said at the break that Arizona had trouble figuring out USC’s zone, and most of the Wildcats’ success came via drive and kick opportunities.
After Arizona took the early lead, both teams traded baskets before the Wildcats were able to create some space toward the end of the half.
Simmons — who didn’t make much of an impact in the beginning of the first half because of foul trouble — hit a 3 from the wing on an assist from a driving Parker Jackson-Cartwright to make it 22-15 with four minutes to play. Then Arizona’s defense forced a turnover which led to a breakaway layup for Simmons to make it 24-15.
Simmons finished with 10 points and three assists. Jackson-Cartwright had three assists, but also three turnovers, was 0-6 from the field and 0-5 from 3.
A layup by Allen made it 26-16, but then Stewart (finally) hit USC’s first 3 of the game to cut Arizona’s lead to 26-19 with under a minute to play.
The Trojans missed their first six 3-pointers, some of which were open looks.
Arizona would quickly get back to a double-digit lead, though, as Markkanen drilled a 3 of his own from the corner to make it 29-19, which would be the score at the break.
Arizona shot 46 percent from the field in the first half and 5-14 from 3, while USC shot 1-10 from behind the arc and 26 percent from the field.
Markkanen led all scorers with eight first-half points.
Ristic finished with 12 rebounds, but did not get many touches on offense, scoring seven points on 2-5 shooting. Allen finished with 11 points, four rebounds, and two steals.
Allonzo Trier missed his 19th game as he continues to be suspended for failing a performance-enhancing drug test back in September.
Arizona returns to action Saturday when it faces No. 3 UCLA at Pauley Pavilion. It’s safe to say the Wildcats will have to put in a more complete effort to beat the high-powered Bruins.
You can follow this author on Twitter at @RKelapire