Despite trailing for most of the first half in Salt Lake City, the Rockets were able to produce a convincing display in the final two quarters to claim a 104-93 triumph.
"We put ourselves to the test. Being down 16 at half time, we might have just caved in and gave up last year but this year we fought back. That's the difference," Harden told journalists after the game.
"In the first half, we were just letting them score, letting them make their cuts, and doing whatever they wanted. They were out-hustling us.
"In the second half, it was vice versa. We got every loose ball, rebounded the ball and got out in transition. We played our basketball."
The Rockets have won their first three games of the season.