The lights went out unexpectedly at the O2 Arena, causing the start of the match between Dominic Thiem and Andrey Rublev at the ATP Finals to be delayed Thursday.
The already-qualified Thiem was short of energy, too, when play eventually began.
The U.S. Open champion lost to Rublev 6-2, 7-5 in a contest that had little real consequence for either player, with Thiem assured of being the winner of the group after previous victories over Stefanos Tsitsipas and Rafael Nadal and his Russian opponent unable to qualify for the semifinals after back-to-back losses.
Tsitsipas and Nadal will meet later Thursday to decide who advances along with Thiem.
Rublev played like someone with nothing to lose, overwhelming Thiem with his serve and fierce groundstrokes to take the Austrian’s first two service games and clinch the first set in less than 26 minutes. He dropped only three points on serve and had no unforced errors in that set.
The second set was much closer, though Rublev was on top and serving at 4-3 when he lost eight straight points to get back on serve.
Rublev regrouped, broke Thiem after a long next game featuring some intense rallies, then served out the match for his first win in his debut at the season-ending tournament.