After relatively smooth sailing during interim head coach Bob Cantu’s first three games, the Trojans’ ship capsized Saturday in Tucson. Following a heartbreaking overtime loss at Arizona State on Thursday, the Trojans tripped out of the gate and never regained their stride in a 74-50 defeat at No. 6 Arizona.

Wheels fall off · After shooting a blistering 15-28 from 3-point land on Thursday against Arizona State, USC went cold on Sunday, making only five shots on 20 3-point attempts in a lopsided loss at Arizona. – Chris Pham | Daily Trojan

The 50 points is USC’s lowest scoring output of the year, and the Trojans fall to 8-13 (3-5 in Pac-12 play) on the season.

Senior point guard Jio Fontan led the Trojans with nine points in USC’s first game this season to have no players in double-digit scoring but also had four turnovers. USC’s starting five shot 7-of-37 (18.9 percent) from the field, and sophomore guard Byron Wesley and senior forward Renaldo Woolridge each scored eight points for the Trojans.

“[Fontan] just has to continue to be the quarterback, play with poise and be at the point where we need to move forward,” Cantu said on Fontan’s struggles in directing the offense.

In what is becoming a routine occurrence, the Trojan 7-footers failed to make an impact. Junior forward Dewayne Dedmon had three blocks, no points and four fouls in a mostly unimpressive performance. The same goes for junior center Omar Oraby, who contributed little besides four fouls, a turnover and a missed shot in 12 minutes.

The Trojans shot 28.1 percent from the floor, including just more than 22 percent in the first half, and a 10-0 USC run in the final two minutes and 22 seconds made the game seem more competitive than it really was.

“We weren’t making shots, we weren’t getting stops and we just got ourselves in a hole early and had a tough time getting out of it,” Cantu said.

The Trojans were out of it from the start, not scoring until their seventh possession and falling in a quick 6-0 hole. That deficit turned into 12-2, then 18-4 with 13:36 left in the half after back-to-back 3-pointers. For every USC basket, the Wildcats seemed to answer with three of their own.

Making just one field goal in the first seven minutes did not help the Trojans’ case, as putrid field goal shooting, a Wildcat lockdown on USC’s starting trio of guards and needless turnovers translated into a 29-7 deficit with eight minutes left in the opening half. After scoring 64 points against Arizona State on Thursday, the trio of Fontan, Wesley and junior shooting guard J.T. Terrell combined for just 20 points against the Wildcats.

“We came out really sluggish offensively, and Arizona came out very aggressively on defense and just took us out of our offense,” Cantu said. “Shots weren’t going down early, and they were for us in previous games.”

Junior forward Ari Stewart had an easy dunk and quick layup to finish the half, but the Trojans trailed 39-20 at the break.

A 19-point deficit was as close as the Trojans got. In the second half, it took the Trojans eight minutes to score their second field goal as Arizona took a 9-1 run to make it 52-25 with 13:03 left in the game. At this point, the Trojans were toast in Tucson.

“Basketball is a game of momentum, and we didn’t have momentum at any point of this game,” Cantu said.

The Wildcats were led throughout the second half by guard Nick Johnson, who led all scorers with 14 points and came up with easy baskets by taking advantage of USC’s struggles in transition and post defense.

USC struggled on defense to block off Arizona’s passing lanes, and the Wildcats’ speed and constant ball movement led to all too many open layups or dunks by Arizona big men making cuts or coming off screens.

The epitome of the Trojans’ struggles Sunday afternoon came with a little more than eight minutes left in the game, when Arizona’s Johnson stutter-stepped right by Wesley and two other USC defenders, then coasted on the baseline for a reverse slam that looked more a dunk contest entry than an in-game bucket.

Arizona took a 74-40 lead with 2:58 left, tied for USC’s largest deficit of the season. By then, the benchwarmers from both sides were in the game.

The Trojans finished strong on a 10-0 tear, including freshman forward Strahinja Gavrilovic’s first points of his college career, but the scoring burst was about 30 minutes too late.

Undoubtedly upset at this lopsided defeat, USC must regroup in a hurry, as their next game comes Wednesday at UCLA, who fell to Arizona State on Saturday, 78-60.

The Trojans lost all three meetings against the Bruins during the 2011-12 season.