The freshman quarterback with a chance to start the Sept. 5 opener against San Jose State was given every opportunity to show he could handle the task.
Barkley took all of the first-team snaps and some second- and third-unit snaps as well during the 72-play scrimmage.
"I was a little tired out there, but it's work and I'm liking it," Barkley said.
Coaches and the fans who lined the sidelines mostly liked what they saw from Barkley on a day when junior Mitch Mustain made a pitch to be more than simply the odd man out in USC's quarterback picture.
As Aaron Corp looked on after going through a series of stress tests on his injured left leg, Barkley mostly impressed and Mustain had perhaps his best scrimmage since transferring to USC in 2007.
"I finished the day strong and thought I played pretty well," said Barkley, who completed 10 of 17 passes for 120 yards in seven series, five against the first-team defense.
Barkley led a drive against the starters that ended with Jordan Congdon's 22-yard field goal. He also connected with receiver David Ausberry on a 19-yard touchdown pass play and ran for an eight-yard touchdown, both against the No. 2 defense.
Safety Will Harris, playing with the starters, intercepted a Barkley pass.
"It was a mixed-up play from the signals, so it was kind of botched from the start," Barkley said. "And I just made a bad decision -- I should have thrown it out "
Overall, however, Coach Pete Carroll said, "I thought Matt handled himself beautifully."
Quarterback coach Jeremy Bates also praised Barkley.
"He made some checks, made sure people got in the right position, and that's part of playing quarterback," Bates said. "It's not just dropping back and throwing it. You're the CEO of the offense and you've got to control everything."
Meantime, Mustain was limited to three series with the second unit and one with the third.
Rather than going for the home run, he mostly threw under coverage and completed his first eight passes before freshman De'Von Flournoy dropped one.
Mustain finished 14 for 16 for 154 yards with no interceptions and connected with Flournoy on a 28-yard scoring pass against the third-team defense. He also led a drive that culminated with Curtis McNeal's short scoring run.
Mustain, who was 8-0 as a freshman starter at Arkansas, is clearly itching for more of an opportunity.
"I'm not here for the hell of it, but it is what it is right now," Mustain said. "I'm just going to keep fighting for it."
Bates said it was by design that Barkley was given all of the first-team snaps.
Asked if Mustain could make a run to become the starter, Carroll said, "He keeps putting days together like this, I think so. . . . Anything can happen. Right now, he's still behind Matt and Aaron."
Trainers had Corp execute several exercises in the weight room and also had the sophomore test the stability of his left leg as he dropped back to pass.
"It's definitely getting better and the swelling has gone down," Corp said. "We'll do more [today] and if it keeps going well I should be back out there soon."
McNeal rushed for 59 yards in seven carries. . . . Linebacker Shane Horton made five tackles. . . . Joe McKnight fumbled on a punt return. . . . The Trojans practice today at 9 a.m. and 4 p.m.