Tebow scored on the ground the first quarter and hooked up with Eric Decker on a long touchdown pass late in the game as the Broncos (4-5) won for the third time in four contests.
The Denver signal-caller ran nine times for 43 yards, helping to make up for the loss of leading rusher Willis McGahee, who left with a hamstring injury.
Fellow running back Knowshon Moreno also suffered a knee injury in the contest.
Denver's defense was tough, holding the Chiefs to only two third-down conversions for the game.
Kansas City (4-5) got only 93 yards and one touchdown pass from Matt Cassel.