The change worked, as USC won seven of eight games to close out the regular season and put themselves in position to claim an NCAA tournament berth, starting with a road victory at California.
And with the Trojans scuffling at the start of Thursday afternoon's quarterfinal game against the Golden Bears, star forward Nikola Vucevic struggling to get in an offensive rhythm and sitting long stretches because of fouls, it was the duo of Smith and Jones that again came to the rescue.
The two combined for 30 points as the Trojans pulled away from Cal for a resounding 70-56 win to advance to the semifinals of the Pac-10 tournament at Staples Center.
The Trojans (19-13) will now face Arizona on Friday evening at 6 p.m., where another win is likely to put them into the field of 68.
Jones was able to penetrate the Bears man-to-man defense seemingly at will, scoring eight of his team-high 16 points in the paint.
Smith added 14, making 4 of 6 shots from behind the 3-point line, helping overcome a poor game by Vucevic.
"Nik's carried us in a lot of games. It was our turn to carry him today and the guys did a great job of that," O'Neill said.
Held to six points in a 68-66 home loss to Cal (17-14) back in January, Vucevic was never able to get into the flow of the game, finishing with just seven. The junior seemed tentative from the start, missing all three of his field goal attempts before picking up a second foul with 8:13 left to play in the first half.
But Vucevic's exit forced the Trojans to play small ball, exploiting penetration by Jones and junior Jio Fontan to close on a 23-11 run capped by Marcus Simmons' 3-pointer at the buzzer for a 35-27 lead.
"We really had trouble keeping their quick guards in front of us," Cal coach Mike Montgomery said.
"I thought every one of our guards was tremendous tonight on the defensive end and on the offensive end. That to me was the difference in our game," O'Neill said.
"We played better defensively without him because of Marcus' quickness."
Cal continued to play man-to-man, despite USC's well-documented troubles against zone defenses after the break, and the Trojans continued to take advantage by shooting 50 percent from the floor.
The Bears played zone almost exclusively in the first two meetings.
Alex Stepheseon added a double-double with 14 points and 16 rebounds. His six offensive boards helped USC post a decisive 14-2 advantage in second chance points.
Pac-10 Freshman of the Year Allen Crabbe had 21 points for Cal to lead all scorers.