PORTLAND, Ore. — Freshman Demetri Goodson streaked the length of the court and made a short, running bank shot with 0.9 seconds left, lifting fourth-seeded Gonzaga over Western Kentucky 83-81 today in the second round of the NCAA tournament.

Gonzaga (28-5) advanced to the South Region semifinals to play top-seeded North Carolina on Friday in Memphis, Tenn. The Tar Heels defeated LSU 84-70.

Steffphon Pettigrew hit a tip-in for the 12th-seeded Hilltoppers (25-9) that tied it at 81 with 7.2 seconds left. But Goodson took the inbounds pass and went straight to the basket with little resistance, hitting from close on the left side.

Western Kentucky, which made a surprise run to the regional semifinals last year, was led by Orlando Mendez-Valdez with 25 points.

This was the 11th straight victory for the Zags, who won the West Coast Conference regular-season title and tournament. The Hilltoppers won the Sun Belt Conference.

Josh Heytvelt's layup with 7:34 left made it 67-64, and he made a bank shot and free throw that put Gonzaga ahead 81-72 with 2:14 left.

But Orlando Mendez-Valdez hit a 3-pointer to make it 81-77 with 1:30 to go. After a Zags turnover, Mendez-Valdez hit Pettigrew for a breakaway dunk with 58.7 seconds left that made it 81-79. Pettigrew's tip-in tied it.

Matt Bouldin had 20 points and eight rebounds for Gonzaga. Jeremy Pargo added 18 points.

Mendez-Valdez had 25 points, including seven 3-pointers, for the Hilltoppers, who had won eight straight going into the game. A.J. Slaughter had 24.

The Zags have made the round of 16 five times in the past 11 years — this is their first trip there since 2006. They burst onto the national scene in 1999 as scrappy mid-major underdogs who reached the final eight.

Last season Western Kentucky upset its way into the regional semifinals. As the 12th seed, the Hilltoppers first defeated Drake 101-99 on Ty Rogers' 30-foot buzzer-beater, then beat San Diego 72-63 before falling 88-78 to UCLA.

The Hilltoppers pulled off another upset on Thursday when they held off fifth-seeded Illinois 76-72 to advance. The Zags defeated Akron 77-64 on Thursday.

Western Kentucky took a first-half lead to 31-25 on Jeremy Evans' jumper. Gonzaga, the taller of the teams, struggled to keep up with the Hilltoppers' creative guards.

Heytvelt, Gonzaga's top scorer, did not score until a dunk that narrowed it to 35-32 with 2:10 to play before the break. Heytvelt was averaging 15.1 points.

Western Kentucky held on for a narrow 37-35 advantage at the break. Mendez-Valdez had 17 first-half points, including 5-for-7 on 3-point attempts.

Bouldin's layup and free throw to open the second half gave Gonzaga the lead, and Pargo added a 3-pointer to extend it.

Last season, Western Kentucky and Gonzaga played in the Great Alaska Shootout with the Zags coming out on top, 74-71. It was their only prior meeting.