Arizona Wildcats forward Grant Jerrett (33) watches as teammates do a free throw before the game against the USC Trojans at the Galen Center. Wednesday February 27, 2013 Los Angeles, California.

Mamta Popat / Arizona Daily Star

LOS ANGELES – The Arizona Wildcats’ defense failed again Wednesday, and this time it wasn’t just for a half.

In the Arizona Wildcats’ 89-78 loss at USC, the Trojans shot 58.1 percent in the first half and kept going in the second – hitting easy and tough shots alike en route to a 61.1 percent total.

Thanks to its shooting, USC took a 42-36 halftime lead and never gave up the lead in the second.

The loss dropped Arizona to 23-5 overall and 11-5 in the Pac-12, where the Wildcats fell a game behind first-place Oregon in the loss column. USC improved to 13-15 and 8-7.

It was Arizona’s third loss in its past six games.

Solomon Hill led the Wildcats in scoring with 21 points while fellow seniors Kevin Parrom had 16 and Mark Lyons 14. But Lyons needed 12 of 16 free-throw shooting to get his points, going 1 for 8 from the field.

Eric Wise led USC with 22 points while Byron Wesley had 18.

Seven footers Omar Oraby of USC and Kaleb Tarczewski of UA both fouled out late in the second half. When Tarczewski left with 3:50 left, USC was ahead 75-68 with 3:50 to go.

Oraby earlier left the game with four points, eight rebounds and four blocks.

Despite rallying late in the first half to cut USC’s lead to just six points at halftime, Arizona struggled early in the second half. USC took leads of 51-38 and 60-50 before the Wildcats climbed back within four points thanks to threes by Parrom and Jordin Mayes.

It was the first three pointer Mayes had made since UA’s Feb. 2 win at Washington State. Mayes did not attempt a three in either of UA’s past two games.

In the first half, Arizona’s defense allowed an opponent to shoot 50 percent or better in a half for the fourth time in the past six games, a trend that cost them games at Colorado and against California at home.

The Wildcats’ defense did wake up just before the end of the half, however, cutting USC’s lead from double digits to just six points thanks to two late steals by Solomon Hill and a block by Parrom.

Hill went coast to coast after one of his steals, cutting USC’s lead to 42-35 while Mark Lyons drove inside with 3.6 seconds left, drew a foul and made 1 of 2 free throws.

Lyons missed all three three-pointers he took in the first half, but he drove inside repeatedly and drew fouls. Ultimately, though, he made just 5 of 9 free throws in the half.

Hill led both teams in scoring in the first half with 12 points while Eric Wise had 11 for USC and Byron Wesley added 10.  Wesley, who entered the game as the leading three-point percentage shooter in Pac-12 games (48.3 percent), hit both three-pointers he took while Jio Fontan was 2 for 3.

Arizona stayed with the Trojans early, leading 11-10 after the first five minutes but USC went on a 16-4 run in the middle of the first half to take a 30-22 lead. At that point, the Trojans were shooting 61.9 percent from the field.

Arizona now will have two days in Los Angeles to prepare for a Saturday game against UCLA at Pauley Pavilion.