Serena Williams was given a right royal Wimbledon scare before battling past teenager Kaja Juvan.
Watched by her friend Meghan Markle, the Duchess of Sussex, Williams scraped through 2-6 6-2 6-4 on No. 1 Court.
American Williams was far from her best against 18-year-old Slovenian Juvan but showed fighting spirit after dropping the opening set to book a place in round three.
Juvan, a girls' doubles champion two years ago at the All England Club, won through three qualifying rounds to make the main draw for the first time, and beat Kristyna Pliskova in her opener.
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Williams, jolted by her slow start, looked down at the court frequently, perhaps concerned by how the grass has already begun to look heavily worn by day four of the championships.
But once she moved up a gear, there was little doubting the outcome, Williams relieved in the end to come through.
"I thought she played well," Williams said of Juvan. "She returned well. I wasn't hitting any big serves.
"I couldn't even ace her during the match because she was really reading the returns. She played well and I started out a little slow."
Her 105th match at #Wimbledon is a winning one.@serenawilliams is pushed all the way by 18-year-old Youth Olympics gold medallist Kaja Juvan to advance to the third round pic.twitter.com/qi8xr6PyLv
— Wimbledon (@Wimbledon) July 4, 2019
With pressure mounting, Williams was relieved to go through the gears.
"It brings the best out of me - I like the pressure," she told BBC Sport. "I play my best when I'm down sometimes so I'm just a fighter and I never give up."
Asked about her mixed doubles partnership with Andy Murray, Williams added: "I'm excited to play with a British icon like Andy. It's going to be incredibly amazing.
"Honestly, I feel really honoured to share a court with him. Maybe I could learn a thing or two – I'm always open."
STATISTICAL BREAKDOWN
Serena Williams [11] bt Kaja Juvan 2-6 6-2 6-4
WINNERS/UNFORCED ERRORS
Williams - 25/26
Juvan - 12/23
ACES/DOUBLE FAULTS
Williams - 6/5
Juvan - 4/3
BREAK POINTS WON
Williams - 4/10
Juvan - 3/3
FIRST SERVE PERCENTAGE
Williams - 54
Juvan - 65
PERCENTAGE OF POINTS WON ON FIRST/SECOND SERVE
Williams - 77/52
Juvan - 60/55
TOTAL POINTS
Williams - 81
Juvan - 73