World number one Iga Swiatek beat Daria Kasatkina in straight sets to make a winning start at the WTA Finals.
That is the most main draw straight-set wins recorded in a single WTA season since Serena Williams (66) and Agnieszka Radwanska (46) in 2013.
Meanwhile, French world number six Caroline Garcia, who plays Swiatek next, defeated Coco Gauff 6-4 6-3.
Garcia, 29, is making her return to the singles competition at the season-ending finals after a five-year absence
Swiatek saved two break points before taking a 3-0 lead against world number eight Kasatkina with a forehand winner in Fort Worth, Texas.