LAWRENCE, Kansas (Ticker) -- After the debacle against Richmond, Kansas left nothing to chance.

Wayne Simien scored 16 of his 20 points in the first half and grabbed 15 rebounds as the 10th-ranked Jayhawks coasted to their 21st straight home victory over Big 12 Conference rival Colorado, 78-57.

Kansas (12-3, 4-0) was stunned by unranked Richmond at home on Thursday, managing only three baskets in the final eight minutes. The Jayhawks avoided any chance of an upset with an early 27-9 run that helped them build a 41-21 halftime lead.

"It was a really good bounce-back game from the disappointment we had against Richmond, especially being a conference game," Simien said. "Right now is the time we're really going to get the bulk of the conference schedule, the tougher games. I feel like this win will help get us going."

Lamar Harris scored a career-high 21 points for Colorado (10-6, 2-3), which has lost back-to-back games after a four-game winning streak.

Keith Langford and freshman J.R. Giddens each scored 13 points for Kansas, which has not lost in Lawrence in the series since February 10, 1983.

After struggling from long range against Richmond, the Jayhawks were 8-of-18 from 3-point range, including 3-of-5 by Giddens.

Colorado shot just 29.3 percent (17-of-58) and made just 3-of-16 shots from 3-point range. Forward Michel Morandais made just 3-of-15 shots from the floor and finished with 10 points.

The Buffaloes got little help in the middle as center David Harrison had five points and two rebounds and fouled out in just 14 minutes.

"I thought that we played pretty well in the game, but once we lost David we were not the same team," Colorado coach Ricardo Patton said. "We didn't make shots, and regardless of how hard you play on the defensive end, sometimes you have to put the ball in the basket."

Colorado led 10-8 less than five minutes into the game before Simien scored four points to start the 27-9 run that he ended with a basket.

"It was probably the best first half, as far as being efficient, that we played all year," Kansas coach Bill Self said.

Kansas led by as many as 33 points in the second half.