Serena Williams loses in first round of Miami Open

KEY BISCAYNE, FLA. » Serena Williams lost in the first round of the Miami Open on Wednesday, still rusty in her return from pregnancy and unable to overcome a tough draw against Naomi Osaka, who won 6-3, 6-2.

The 20-year-old Osaka, who earned her first career title Sunday at Indian Wells, showed no signs of letup and overpowered the erratic Williams. Osaka had the stronger serve, and in rallies wore down Williams working her from side to side.

The matchup worthy of a final came about because both players are unseeded. Osaka is ranked a careerbest 22nd, while Williams’ ranking is 491st after her layoff of more than a year.

Another new mother and former No. 1, three-time Key Biscayne champion Victoria Azarenka, defeated Catherine Bellis 6-3, 6-0.