Leading the scrappy Pilots with 16 points, Pressley's voice was totally gone by the raucous postgame celebration after Portland beat the No. 22 Bulldogs 82-73 on Thursday night.
The victory snapped a 20-game losing streak to Gonzaga.
"I mean, it's Gonzaga. Naturally, you're going to get pumped up," Pressley said, mustering barely a whisper. "But it was a team effort, coaches and players included. We all just got fired up and we took care of business."
The last time Portland (10-7, 2-3) beat Gonzaga at home was in 1996 and the Pilots' last victory in the series came in 2003 in Spokane. Portland had not defeated a ranked opponent since 2009 against then-No. 22 Minnesota.
Gonzaga (14-3, 4-1) had won four straight to open the conference season after a 72-62 loss to Kansas State on Dec. 21.
Playing in their first league game away from home, the defending conference champions were coming off an 86-54 victory over Pacific last Saturday. The Zags won their first four conference games by an average margin of victory of 21.5 points, and they'd held their last six opponents to fewer than 62 points.
However, the Pilots (10-7, 2-3) were determined from the start, stretching their lead to as many as 17 points in the second half.
"They were flying around and beating us to pretty much every ball that was available," Bulldogs coach Mark Few said. "I thought they outplayed us on offense and they outplayed us on the defensive end. We didn't execute very well until there at the end and they deserve a lot of credit.
Back-to-back jumpers from Riley Barker and Bryce Pressley put the tenacious Pilots up 49-37 with 15:26 left. Portland pushed the lead to 53-37 on Kevin Bailey's falling-down jumper and a free throw -- and Gonzaga appeared to be pressing.
Gerard Coleman's layup and two free throws narrowed it to 76-65 for the Bulldogs before Drew Barham's layup made it 78-71 with 1:05. However, Portland held off the Zags as time wound down and Portland's purple-clad fans rushed the court in celebration.
Alec Wintering, who retreated to the locker room in the second half because of cramping in his legs bur returned before the finish, had 14 points for the Pilots and Bailey added 13.
Sam Dower led Gonzaga with 14 points off the bench. Leader scorer Kevin Pangos was held to 12 points.
"We never quite got our feet ready and Portland did a great job of making shots and flying around and basically just outplaying us all night," Few said.
The Pilots were coming off a 72-63 loss to St. Mary's. The game against Gonzaga wrapped up a five-game conference homestand for the Pilots.
Before the game, coach Eric Reveno told the team: "Have the courage to take it.
"I'm glad we beat them when they're pretty good. They're maybe not as dominant as the No. 1 seed they were last year, but they're a good basketball team," Reveno said. "It would have soured it for me if they weren't a good basketball team. I do enjoy beating a good basketball team, darn straight."
After the game, Reveno -- now 1-14 against Gonzaga -- said Few came over with a genuine smile and told him, "Nice job."
Portland is now 7-54 all-time against ranked opponents. Earlier this season the Pilots fell 82-67 at then-No. 1 Michigan State.
Portland jumped out to an early 11-5 lead, paced by Bailey with six points, but Pangos hit a 3-pointer and Angel Nunez dunked to narrow it for the Zags.
It was as close as they could get, and Portland stretched the lead to 20-13 after a pair of free throws from Bailey. With all the momentum on their side, the Pilots pushed the lead to 30-19 following Pressley's layup.
The Zags looked like they were caught off guard by Portland's energy and trailed 39-31 at the half.
"Awesome. It's almost surreal," said 6-foot-11 Portland center Thomas van der Mars, who finished with 11 points and five rebounds. "My teammates had so much confidence. When you play like that it's really fun."
Gonzaga's 7-foot-1 center Przemek Karnowski battled the flu earlier this week but started. The Bulldogs remain without guard Gary Bell, who broke his hand against Santa Clara on Dec. 28 and is expected to be out up to six weeks.