After leading the Pac-12 in defensive efficiency during the regular season, USC’s defense remained stellar Saturday, holding Drake to just 19 second-half points en route to a 72-56 victory in the first round of the NCAA Tournament.

Although just one Trojan — redshirt senior forward Chevez Goodwin — had any prior NCAA Tournament experience, USC played like a mature team thanks to head coach Andy Enfield, who came in with a 4-3 record in the tournament. Enfield famously led Florida Gulf Coast to the Sweet Sixteen as a No. 15 seed in 2013.

“I thought our guys really kept their composure the entire game,” Enfield said. “We limited our turnovers, we had a lot of assists … Once you get into the flow of the game, we realized we’ve been here before.”

Drake, which started 18-0 this season, finished the regular season 24-3 and gained an at-large bid as a No. 11 seed from the Missouri Valley Conference. The Bulldogs grinded out a tough 53-52 victory against Wichita State in their First Four matchup on Thursday, led by sophomore guard Joseph Yesufu’s 21 points.

USC held a slim lead much of the first half, thanks to field goals from six different players in the first 10 minutes. The Trojans had a significant height advantage at almost every position, especially at shooting guard, where 6-foot-8 junior Drew Peterson matched up against Drake’s 6-foot-2 junior D.J. Wilkins.

Still, Yesufu, who has been starting in place of redshirt junior guard Roman Penn since a left foot injury ended his season, kept the Bulldogs close with a stellar first half, including 18 points on 4-of-6 3-point shooting. Drake’s leading scorer and rebounder, senior forward ShanQuan Hemphill, came off the bench in just his second game back from a foot injury and contributed with six points early.

“We didn’t really lock up on [Yesufu] the entire possession,” freshman forward Evan Mobley said about his team’s early defensive struggles.

Like Peterson’s, Mobley’s height caused issues for Drake, as the young phenom dominated in the paint on both ends of the court. The Trojans outscored the Bulldogs 26-10 in the paint in the first half, helping USC take a 40-37 lead into halftime.

However, as effective as USC was in the interior, Drake was the much better team on the outside early in the game. The Trojans’ season-long struggles at the charity stripe remained an issue, as USC made just three of nine free throws in the first half, including misses on four different and-one opportunities. Meanwhile, Drake shot 56% from three and 86% from the line in the first half.

USC pulled out to an 11-point lead after an 8-0 run early in the second half. The Trojans’ highly touted defense took over and began to force Drake into tougher shots, as the Bulldogs began the half 2-of-23 from the field.

“Our goal was to take their best player out of the game in the second half and make everything tough,” Enfield said of his halftime defensive adjustments. “We did a good job of switching man and zone and we made him work.”

The USC guards concentrated on stopping Yesufu, who cooled off after his hot start and finished with 26 points on 8-of-22 shooting. The strategy worked fantastically, as the Trojans held Drake to just 19 points and 19% percent shooting in the second half.

The Bulldogs appeared noticeably fatigued in the second half, likely due in part to both a shorthanded rotation (Hemphill was only able to play six minutes) and the Trojans’ size advantage, forcing Drake to work harder on both ends.

After his brother missed a three, Evan Mobley converted an easy putback to extend the USC lead to 15 with 2:35 to go in the game, all but putting away the Bulldogs. The Pac-12 Player of the Year, Freshman of the Year and Defensive Player of the Year backed up his accolades with another impressive statline, finishing with 17 points, 11 rebounds and three blocks to guide his team to the second round.

Although he had some foul trouble, sophomore forward Isaiah Mobley provided more offense for USC with 15 points on 6-of-7 from the field.

“When [Isaiah Mobley] came back into the game, he was sensational in posting up and getting position and finishing with his jump hook,” Enfield said.

Peterson also contributed 14 points, and redshirt senior guard Tahj Eaddy created plenty of scoring opportunities in the paint, supplying a season-high 10 assists along with nine points and six rebounds.

After his first NCAA Tournament game, Evan Mobley emphasized the performances of his teammates.

“When other players are a threat on our team, [opponents] got to lock in on them more, which leaves other players open, like me or anybody else,” Mobley said.

USC will take on No. 3-seeded Kansas Monday in the Round of 32.