Serena Williams begins U.S. Open with first-round win

Serena Williams' potential final singles match got off to an inauspicious start at the U.S. Open on Monday night as her serve — the greatest ever's greatest weapon — looked out of sorts in the first few games.

• Then she shook off the nerves, settled in, and did what she always does at Arthur Ashe Stadium: dominated.

"I haven't seen Serena play like this in five years. I really haven't."

Match recap: Williams, 40, defeated Montenegro's Danka Kovinić in straight sets, 6-3, 6-3, in front of a star-studded, sold-out crowd of nearly 24,000.

• Both players were clearly affected by the spectacle in the early going, but the much younger Kovinić, 27, was better able to grind out games.
• But once Serena's serve started cooperating, her confidence skyrocketed and Kovinić, frankly, didn't stand a chance.

By the numbers: After landing just four of 16 first-serves to start the match (25%), Serena made 39 of her final 49 (80%). Her nine aces were the third-most among the 64 women who played Monday.

What's next: Kovinić wasn't exactly an easy out, but Serena's next opponent should be a much bigger challenge as she's set to face No. 2 Anett Kontaveit on Wednesday.

The bottom line: Serena's now won U.S. Open matches in her teens, 20s, 30s and 40s. One-of-a-kind doesn't even begin to describe her.

• At this point, only one question remains: Is she going to make a run at this thing?