Li fights back to beat Keys
Li Na finally got her campaign at the Sony Open Tennis in Miami under way with a 7-6 (7-3) 6-3 victory over Madison Keys.
The world No 2 received a bye in the opening and a walkover in round two and showed some signs of rust during her hard-fought win over the American teenager.
Keys, who lives in nearby Boca Raton, threatened the Australian Open champion on several occasions but ultimately could not take advantage of the opportunities.
"I think it was a pretty tough match, she played well, big serve, big forehand, especially when she was 3-1 down and then came back (to) 5-3 and served for the first set," Li said.
"During that time I didn't think about too much. I said, 'OK try to hit the ball, try to do what you have to do and save the set point'.
"I think this maybe changed the match a little bit because after that I was feeling (that) she dropped a little bit."
Li had started well to move a break up in the first before Keys reeled off four straight games to take control. However, the second seed fought her way back into contention and took the set in a tie-break.
Keys again had her opponent under pressure early in the second set but fell apart after taking a 2-0 lead.
"She's No 2 in the world for a reason. She just won Australian Open for a reason. She's a great player," Keys said.
"I played well at times and she just played the bigger points really, really well. There is a lot to be happy with but there is also some stuff I need to work on."
Li will next face 15th seed Carla Suarez Navarro, who coasted to a 6-2 6-1 victory over Kaia Kanepi on Sunday.
Third-seed Agnieszka Radwanska is also safely through to the last 16 after the Pole clinched a 7-5 6-3 win against Russia's Elena Vesnina.