For 34 minutes, Missouri shut down West Virginia's prolific 3-point offense.
Then Missouri lost its focus, according to guard Jordan Clarkson.
The Tigers won 80-71, but only after surviving a late 17-5 run by the Mountaineers. The scare gives Missouri (8-0) something to work on as its welcomes 18th-ranked UCLA to Mizzou Arena on Saturday.
"I think we allowed them to get into the paint," coach Frank Haith said. "We gave up some broken plays where we weren't back setting our defense. They had some plays where we bobbled some loose rebounds, and they stuck it in."
The Tigers also opted to try to score after grabbing offensive rebounds, rather than working the ball to the perimeter to burn time.
West Virginia (6-3) settled for making 42 percent of its shots after entering the game averaging 85.1 points and shooting nearly 50 percent. The team only made eight of 29 shots in the first half.
"We didn't score seemingly for about an hour and a half," West Virginia coach Bob Huggins said. "So I would say we probably shot ourselves in the foot. Or blew our heads off."
Clarkson scored 25 points and guard Jabari Brown added 18 for the Tigers, who shot 53 percent.
Missouri extended its national-best home-court winning streak to 23 games and has won 78 consecutive games at Mizzou Arena against non-conference competition.
"It's tradition," Clarkson said. "We want to keep that going. Just keep protecting the home court. We can't let anybody come in here and do whatever they want to do."
Juwan Staten scored 16 points, while Gary Browne and Terry Henderson added 14 for West Virginia, which fell to 0-3 against power conference teams.
Missouri scored the first nine points and led throughout as West Virginia never established a rhythm until the end of the night. The Mountaineers also averaged 10 3-pointers per game before Thursday, but only converted one of their first 14 attempts until Browne's make with 7:51 remaining. They finished four for 19.
Earnest Ross added 16 points for the Tigers, who have won their first eight games for the first time since the 2006-07 season. Clarkson, Brown and Ross have combined for nearly two-thirds of the Tigers' scoring this season.
Missouri also out-rebounded West Virginia 40-32 after the Mountaineers grabbed 62 boards against Loyola Maryland, their most since 64 in a contest against Radford in 1992. West Virginia had been averaging four more boards per game than its opponents.
"I think this team is really taking our focus on being a better defensive team to heart," Haith said. "We've just got to stay with it."
The Mountaineers used a 9-2 run to pull within 27-20 with 4:36 remaining in the first half, but Missouri countered with an identical run to take a 36-22 halftime lead. After Devin Williams opened the second half with a layup, Missouri then scored the next five points.
West Virginia again narrowed the lead late in the second half, as Staten capped the team's 17-5 run with a layup with 1:45 left to narrow the Mountaineers' deficit to 73-64. After two free throws by the Tigers' Wes Clark, Rémi Dibo drained a 3-pointer from the corner with 1:10 left to make the score 75-67.
But the Mountaineers couldn't get any closer.
Staten (16) and Eron Harris (8) combined for 24 points after only scoring four total in the first half. The duo previously averaged nearly 37 for West Virginia, which has also lost to Virginia Tech and Wisconsin. Coaches picked the team to finish seventh in the 10-team Big 12 prior to the season as the team lost its final seven games last year and finished 13-19.
"I need to realize I have teammates that are very capable, and I need to put my full trust in my teammates," said Harris, who ranks second in the Big 12 with 20.3 points per game. "Not that I don't trust them, but when I'm not getting shots, maybe it's not my day to get shots."
Missouri's new chancellor, R. Bowen Loftin, attended the game and was introduced to fans in the first half. He then went into the stands to shake hands and pose for pictures with students. Currently the president of Texas A&M, Loftin will begin his new job as Missouri's leader on Feb. 1.