NEW YORK • Serena Williams bungled yet another shot and wailed: "I keep missing my forehand!"
She was in trouble, if only briefly, against 17-year-old fellow American Caty McNally.
Making key adjustments to her serve and straightening out her other strokes, Williams avoided what would have been her earliest loss in 19 appearances at the US Open, coming back to win 5-7, 6-3, 6-1 on Wednesday.
"You can't win tournaments making that many errors," said last year's runner-up Williams, whose 28 unforced errors were just two fewer than McNally's tally.
"I survived tonight but I am not too pleased with the way I played. But it's OK, I'm still here and happy to be on this court. I'll do better.
"She really came out and played really well, she showed no fear. She had absolutely nothing to lose and she played like it."
Williams improved to 38-0 in the first two rounds at Flushing Meadows. The only time she was beaten as early as even the third round was on her debut all way back in 1998, when she was just 16.
Unforced errors Serena Williams committed in beating teenager Caty McNally.
The following year, she won the first of her six US Open titles. McNally had not even been born yet.
Now 37, Williams owns 23 Grand Slam singles titles, and she showed why while powering her way through a deficit, taking 16 of the final set's initial 17 points.
World No. 121 McNally had never won a match at any Slam until Monday, when she beat Switzerland's Timea Bacsinszky. She received a wildcard invitation from the US Tennis Association for singles and for doubles, the latter with 15-year-old sensation Cori Gauff.
Gauff beat Williams' older sister, Venus, on the way to the fourth round of Wimbledon last month.
Might another stunner be in the offing? It seemed a possibility for a set, with McNally charging the net, serving and volleying, and looking like someone who belonged.
Maybe that was why Williams took time to get into a real groove. She went stretches without being the dominant force who overwhelmed five-time Major champion Maria Sharapova 6-1, 6-1 in her glamour opening tie at the same Arthur Ashe Stadium.
Said McNally: "I didn't think who was on the other side of the net as much. But I knew I was playing against the greatest of all time. I knew I had to bring a certain level.
"I walked out there and I had the chills. That was the most insane atmosphere. It was just an unbelievable experience, something that I'll never forget for the rest of my life."
French Open champion Ashleigh Barty also fought off a stiff challenge at the end of the second set to beat American Lauren Davis 6-2, 7-6 (7-2) and reach the third round.
The Australian came to the net to great effect, proving the more aggressive player as she used her slice to dictate the pace and fired 35 winners.
ASSOCIATED PRESS, REUTERS