Against the Western Conference-leading Denver Nuggets, Capela was only second-best to James Harden's 32 in the points column, propelling Houston to 125-113 win at home.
Houston (23-16) returned to Toyota Center after splitting a two-game road trip that saw it beat the defending champ Warriors.
Harden added 14 assists for a double-double. P.J. Tucker and Gerald Green each added 21 points.
Houston looks to make it 13 wins in 15 games when it hosts its second consecutive conference leader, the East's current No. 1 seed, the Milwaukee Bucks, on Wednesday.