Top-seeded Gonzaga needed all 17 of Kelly Olynyk's second-half points, along with a couple of clutch 3-pointers down the stretch, to dispose of the upset-minded Southern Jaguars, 64-58, in second round play of the NCAA Tournament.
Olynyk scored 21 points for the contest and also had 10 rebounds, but Gonzaga (32-2) was aided in the final minutes by Gary Bell Jr. and Kevin Pangos, both of whom knocked down clutch shots from beyond the arc to preserve the win.
"I think moving forward -- any win in the tournament is a good win," said Olynyk. "So we have to kinda take that into consideration and then moving forward. We got some stuff we can work on and stuff."
Pangos nailed four triples in all for 16 points, while Bell added three from long distance to finish with 11 for the Bulldogs, who will next take on Wichita State on Saturday.
The Southwestern Athletic Conference champion Jaguars gave the nation's No. 1 team a real run for their money and had the score tied with just under four minutes left, but Southern (23-10) couldn't pull off an unprecedented upset by a 16th seed.
Derick Beltran tallied a game-high 21 points and Malcolm Miller followed with nine for the Jaguars, who were making their first NCAA Tournament appearance since 2006.
Behind the second half play of the first team All-American Olynyk, the Bulldogs created an 11-point lead with 9:37 to go, but couldn't shake the pesky Jaguars and their solid 3-point shooting until the final minutes.
Southern, which was 10-for-23 from beyond the arc for the game, was in the midst of a 5 1/2 minute drought without a field goal until Yondarius Johnson canned a triple to spark a 10-2 run.
Beltran, the team's season-leading scorer, followed Johnson's 3-pointer with seven straight points before a pair of Brandon Moore free throws knotted the contest at 54-54 with 4:08 to go.
"I was just in the moment," said Beltran. "I didn't think about it, because we was trying to win. No shot, no possession was bigger than the next. We was just trying to get the win."
Pangos and Beltran then exchanged deep jumpers to keep the contest deadlocked, but Bell's ensuing pull-up 3-pointer put Gonzaga ahead for good.
Beltran drew a foul and sank a pair of free throws to keep the contest within one, but Pangos drilled a triple from the corner the next time down to create a four-point spread which would hold over the final 1:54.
Southern had four 3-pointers in the first 10 minutes, with Beltran's triple putting the Jaguars in front and Johnson's three-point play soon after creating a 19-16 edge.
The Zags, though, reeled off a 9-0 run to take the lead for the rest of the half, with David Stockton's three-point play and Olynyk's score underneath putting the Bulldogs back on top by six and they held a 34-31 lead at halftime.
Fired up by their first half performance, the Jaguars came out of the locker room to pull within 41-40 following back-to-back 3-pointers from Madut Bol and Beltran, but then misfired on their next five shots.
In the meantime, Olynyk took advantage by tearing through paint in scoring 10 of Gonzaga's next 13 points, with his pick-and-roll layup putting the Bulldogs ahead 52-41 with under 10 minutes left to play.
Gonzaga outscored Southern inside the paint, 24-8 ... The Jaguars had eight blocks ... Southern was making just its second tournament appearance since 1993 ... The Bulldogs have made the tournament 15 years in a row.