Serena Williams loses in 1st round

The match in Key Biscayne, Fla., ended with Serena Williams grinning at the net. She saved her worst shot for last, and had to laugh after a rare first-round defeat.

Still rusty in her return from pregnancy, Williams was unable to overcome a tough opening draw at the Miami Open and lost Wednesday to Naomi Osaka, 6-3, 6-2. On the final point, Williams thundered forward to attack an easy shot at eye level, whacked the ball six feet past the baseline and responded with a sheepish smile.

Not that motherhood has mellowed Williams. She left without talking to the media.

Osaka, 20, who earned her first career title Sunday at Indian Wells, said she was nervous at the start, playing her idol for the first time. “She’s the main reason I started playing tennis,” Osaka said. Osaka, who lives in Fort Lauderdale, raised her profile last week and showed no signs of letup, overpowering Williams. The matchup worthy of a final came about because both players were unseeded. Osaka is ranked a career-best 22nd, while Williams’ ranking is 491st after a layoff of more than a year.

Another new mother and former No. 1, three-time champion Victoria Azarenka, defeated Catherine Bellis 6-3, 6-0. Seeded players are in action beginning today.

Williams has been eliminated in the first round only four other times, most recently at the 2012 French Open. The latest defeat came at a tournament she has won a record eight times.