ABU DHABI (AFP) - A slow moving Serena Williams suffered defeat on her comeback from a maternity break as French Open champion Jelena Ostapenko powered to victory in the "first to ten points" final set at the Abu Dhabi exhibition tournament on Saturday (Dec 30).

The 36-year-old Williams looked static and far from full fitness just four months after the birth of her first child and Ostapenko, a 20-year-old Latvian, won 6-2, 3-6, 10/5.

"The first match is always really hard after a break," Williams said.

"I was just glad to be here," she said.

The former world No.1 who gave birth to a daughter in September is hoping to defend her Australian Open title when the tournament gets underway January 15.