Playing her first match as the top-ranked player, Simona Halep beat Caroline Garcia 6-4, 6-2 Monday at the WTA Finals.
"I am really happy I can win the first match (as No. 1)," said Halep, the first Romanian woman to be top-ranked. "It takes the pressure off."
Halep was broken once in the six break points she faced on serve. She surrendered her serve when she double-faulted in the sixth game.
Garcia, making her WTA Finals debut, was broken twice in each set.
Halep, making her fourth consecutive appearance in the WTA Finals, was a finalist here in 2014. She lost to No. 1 Serena Williams on that occasion, which marks the last time the top-ranked player won the season-ending event.
Elina Svitolina of Ukraine and Caroline Wozniacki of Denmark were set to play the late match on Monday.