Federer wrapped up the victory in just 61 minutes, with his haste to end the contest no more evident than in the eighth game of the match.
The 31-year-old is closing in on finishing the year as world No.1 for the first time since 2013.
Swiss icon Roger Federer is also still in contention for the title after a fine display.
The world No.2 was even swifter than Nadal, taking exactly an hour to see off Alexandr Dolgopolov 6-4 6-2. I'm happy I was able to do better today on the break points. "It was really a fast-court match".
While a Nadal-Federer final looms, Argentina's Juan Martin del Potro could ruin the script, as he did at the U.S. Open where he defeated Federer in the quarter-finals when a semi-final between the two greats looked likely.
Sixth seed Grigor Dimitrov, who saved match points on Wednesday against Ryan Harrison, had a more comfortable day as he beat American 10th seed Sam Querrey 6-3 7-6 (7-3).
Bulgarian Dimitrov, who could claim a debut appearance at the ATP World Tour Finals in London next month by reaching the final in Shanghai, plays Nadal next.
Marin Cilic, the fourth seed, was a 7-6 (7-1) 6-4 victor against Steve Johnson, while Grigor Dimitrov got past Sam Querrey to set up an encounter with Nadal.