Emma Raducanu was knocked out of the Miami Open by Canada's Bianca Andreescu after an absorbing first-round match where both players showed glimpses of their huge potential.
The British number one, 20, lost 6-3 3-6 6-2 against 22-year-old Andreescu, who also won the US Open as a teenager.
Both players have been beset by injury but produced a hard-fought match where a single break won the first two sets.
The decider was initially tight before Andreescu won the last four games.
"You never know what you're going to expect, I just wanted to play my best with what I had and I think I did that," said Andreescu, who plays Greek seventh seed Maria Sakkari next.
The British number one, 20, lost 6-3 3-6 6-2 against 22-year-old Andreescu, who also won the US Open as a teenager.
Both players have been beset by injury but produced a hard-fought match where a single break won the first two sets.
The decider was initially tight before Andreescu won the last four games.
"You never know what you're going to expect, I just wanted to play my best with what I had and I think I did that," said Andreescu, who plays Greek seventh seed Maria Sakkari next.