But Nadal, for whom victory gifted him a sixth title of the season and landmark 75th ATP crown, has no doubts about Kyrgios's talent.
Kyrgios still has a chance of qualifying for the ATP World Tour Finals as he is 15th in the Race standings with several tournaments remaining to close the gap on those in front.
The world No 19 was aiming for his first title of the year but fell to a convincing 6-2 6-1 defeat in Beijing. The 31-year-old saved two match points in his nervy opener against Frenchman Lucas Pouille, but was never really in trouble as Kyrgios's final hopes evaporated in acrimony.
Kyrgios displayed his best side in forcing Nadal to 2-2 in the first set, but his other side emerged later.
"I was lucky the first day saving the two match points but after that I think I played one of my best events of the year".
And when he went down 30-0 on Nadal's serve at 2-2, the Australian began the first in a series of lengthy discussions with the umpire - frequently spreading his arms in despair, shaking his head and swearing at least once.
The 22-year-old then collected a penalty point and he continued to rant as he trudged back to his chair, initially to whistles from the crowd and then cheers to encourage him. "He just destroyed me today, so it was too good", Kyrgios, who struck 20 winners but 35 unforced errors, said. Now riding a 12-match win streak, it's Nadal's first title in the post-US Open portion of the season since winning Tokyo in 2010, where he also saved match point en route to the title.
"It's tough to find positives when you won three games in the final. In the semi-final I played well, obviously beating Alex (Zverev)".