Serena Williams says she wants to "move on to bigger and better things" following her first match back since her controversial US Open final defeat by Naomi Osaka.
Williams, 37, was beaten by her sister Venus 4-6 6-3 10-8 in an exhibition match in Abu Dhabi on Thursday.
The 23-time Grand Slam champion subsequently refused to discuss her confrontation with umpire Carlos Ramos in September's final in New York.
"I don't avoid anything," she said.
"I just don't have time to talk about that.
"I talked about it, everyone talked about it for months and months and months and it's best to move on to bigger and better things.