Dustin Hogue added 15 points and 10 rebounds for the Cyclones while Deandre Kane had 14 points, Matt Thomas 13 and Monte Morris 10.
Kane, a Pittsburgh native, had more than 50 relatives and friends in attendance. He went 1-2 against the Mountaineers while he played at instate rival Marshall and was booed and taunted whenever he touched the ball.
"Tonight we just didn't have it," Hoiberg said. "I don't know what it was. This group has been very focused and given everything all year."
West Virginia's lack of bench scoring had stood out in a double-digit loss to No. 7 Kansas on Saturday. On Monday, the Mountaineers' reserves outscored Iowa State's 27-15.
"We had pretty much the same shots against Kansas, but we didn't make them," Huggins said. "Today, we made them."
Trailing 52-33 at halftime, Iowa State put together its best stretch and closed the gap to 58-44 5 minutes into the second half before West Virginia again pulled away.
The Cyclones went 4 minutes between field goals after that, and West Virginia got a big boost from its bench to keep the pressure on. Freshman Nathan Adrian made two baskets and two free throws, and Kevin Noreen doubled his season scoring average with a layup and two free throws.
Dibo's 3-pointer with 6:53 left gave the Mountaineers their largest lead, 86-54.
"We just stuck to the game plan," Dibo said. "We couldn't let them make a run to come back. We knew from the past every time we had a lead, we had let teams come back, and we knew we couldn't let that happen."
The only drama for West Virginia came when Harris was ejected for a flagrant foul with 4:25 left.
After the game, West Virginia's players went into the student section to celebrate.