The sophomore scored a season-high 19 points, Kevin Pangos added 18 and the Bulldogs came from 10 points down to beat West Virginia 80-76 on Tuesday night.
A 7-foot-1 native of Poland, Karnowski had his way against West Virginia's undersized front court, which doesn't have a player over 6-10. Karnowski made 6 of 11 field goals and matched a career high with 13 rebounds for the second double-double of his career.
"The guys were finding me," Karnowski said. "I had great passes, I just had to finish them."
A 48 percent free-throw shooter, Karnowski went 7 of 8 from the line. And he had just one foul called on him after spending half of his games in foul trouble, including fouling out twice.
"We knew coming in that we had a size advantage," Gonzaga coach Mark Few said. "Pzem did a good job in traffic and finished some plays. The best thing that he did tonight was rebound, because any team that (West Virginia's Bob Huggins) coaches is tough and they are going to fight you on the glass."
Gonzaga (9-1) held a 43-36 rebound advantage.
"We did a much better job on Harris in the second half," Few said. "He was lighting us up in the first half."
The Bulldogs entered the game with the nation's best field goal percentage at 54.9 but were held to 44.3 percent (27 of 61) in their first game on an opponent's court this season. Their previous worst was 48.1 percent in a Nov. 25 loss to Dayton in the Maui Invitational.
Gonzaga has won five straight games since.
Gary Bell Jr. added 15 points and Sam Dower scored 11 for the Bulldogs.
As tough as Karnowski was to stop, so too was Pangos down the stretch.
After going 3 of 10 from the field in the first half, the junior went 4 of 7 after halftime. Pangos had 11 points in the final 6 minutes as Gonzaga rallied from down 53-43, its only double-digit deficit this season.
"Kevin kept at it," Dower said. "He didn't give up. He was persistent. He hit some really big 3s and that's what he does. We knew it was coming sooner or later. That lifted up the team's morale as well, and got everybody going."
West Virginia failed to seize on an opportunity to pad its resume and get its first win over a marquee opponent. West Virginia lost in the past two weeks to No. 4 Wisconsin and Missouri.
The Mountaineers were held to one field goal over a 7-minute stretch late in the game.
"I think the whole thing started when we didn't get back on defense," Huggins said. "We are so close to being pretty good, but at the same time, we are so far away."
West Virginia had just five turnovers but was held to its second-worst shooting performance of the season at 37.3 percent (25 of 67). The Mountaineers have lost 13 straight times to ranked opponents.
Pangos hit a 3-pointer with 4:09 left to give Gonzaga the lead for good, 68-66. It was the Bulldogs' first lead of the second half.
Pangos made two more wide-open 3-pointers over the next 2 minutes and Bell made two free throws with 1:52 left to give Gonzaga its largest lead, 76-68.
After Pangos was called for a charge into Harris, Staten hit a basket with 51 seconds left to pull West Virginia within 76-74. But the Mountaineers didn't score another field goal the rest of the game.