Two-time defending champion Novak Djokovic joined Stan Wawrinka in posting a crushing win to open his ATP World Tour Finals campaign in London.
Wawrinka had put a poor run of form behind him with a 6-1 6-1 victory over Tomas Berdych yesterday afternoon that lasted just 58 minutes.
It was the most one-sided result since the tournament moved to Britain in 2009, but it took only a few hours for it to be equalled as Djokovic won by the same scoreline against US Open champion Marin Cilic - and in two minutes fewer.
The Croatian, whose New York triumph was one of the shock results of the last decade, had lost all his previous 10 matches against Djokovic, but their three other clashes this year had all been close.
The world number one is the king indoors, protecting a 27-match winning streak dating back two years and from the moment he hit his stride to break for a 2-1 lead in the opening set, a 28th looked inevitable.
Djokovic was just too good and too solid off the ground, clinching a second straight break with two sumptuous forehand passes.
Cilic saved one set point with an ace but not a second, and Djokovic made it eight games in a row by breaking serve again at the start of the second set.
The one high point for Cilic came with a break to love in the third game, but he was outclassed on his tournament debut.
Berdych's defeat maintains his unwanted record of never having won his opening match at the tournament.