With temperatures once again nudging towards 100 Fahrenheit (38 Celsius), Djokovic turned in a cool, clinical effort, improving his record against American opposition at the US Open to a perfect 12-0.
While Fritz's Grand Slam came to an end, the US is guaranteed at least one player in the men's semi-finals with Frances Tiafoe and Ben Shelton meeting in an all-American clash on Arthur Ashe later on Tuesday with Djokovic waiting to take on the winner for a spot in Sunday's final.
"It's expected of course that people are backing the home player and there is nothing wrong with that," said Djokovic.
"I actually like the energy, like the atmosphere on centre court here.
"Day sessions, night sessions, people are getting into it.
"I'm fine with that. I thrive on that energy and try to use it as a fuel.
"I've been playing on this court for so many years, so many epic matches, I can't wait for another one in a few days' time."
On a baking hot day, 19-year-old Coco Gauff had warmed up the Arthur Ashe crowd, blasting past Latvia's Jelena Ostapenko 6-0, 6-2 to become the youngest American to reach the US Open semi-finals since Serena Williams in 2001.
But Fritz could not keep the party going, although he had his opportunities but could convert only two of 12 break chances while committing 51 unforced errors, almost double his opponent's 26.
Fritz had lost all seven career meetings with Djokovic and never beaten a top-10 opponent at a Grand Slam but rolled into the quarter-finals in sensational form, the only player to not drop a set and broken only once in 50 service games.
Djokovic wasted no time ending both those runs, breaking the American three times and then taking the first set with a booming ace.
Fritz finally held serve to open the second but was soon feeling the pressure again with Djokovic breaking the ninth seed a fourth time to go ahead 2-1 and close out the set in the same emphatic style with an ace.
With the crowd getting behind him, Fritz would offer up more resistance in the third but could not find a way back, with the Serb getting the decisive break at 5-4 and then holding serve - improving to 13-0 in US Open quarter-finals.
