Kyle Edmund missed out on his first win over a top-10 player when he lost to world number four Milos Raonic in the Delray Beach Open quarter-finals.
Britain's Edmund started well and took the first set but the Canadian top seed hit back to win 4-6 6-3 6-4.
Raonic won five games in a row to seal the second set and go 2-0 up in the decider and help set up the victory.
However, Edmund's display at the event means he will regain his status as British number two from Dan Evans.
Raonic will face Argentina's former US Open winner Juan Martin del Potro in Saturday's semi-final.
Seventh seed Del Potro, who won the event in 2011, beat American wildcard Sam Querrey 7-5 7-5.
In the other semi-final, American world number 21 Jack Sock faces compatriot Donald Young, ranked 69.