Andy Murray missed out on a place in the Surbiton Trophy final when American Denis Kudla denied the three-time grand slam champion on Saturday.
Murray had won their one previous match emphatically on a hard court in San Diego last year, and he had early control of the semi-final this time at the Challenger Tour event.
However, Murray could not force a second-set breakthrough and lost the tie-break on the way to a 5-7 7-6 (7-4) 6-3 defeat.
The Scot, a title winner at Wimbledon in 2013 and 2016, served 15 aces to Kudla's 12. Murray won just 45 per cent of points on his second serve, though, an area where he will hope to improve as the grass season progresses.
He heads to Stuttgart next week before playing at Queen's Club in the run-up to Wimbledon.
World number 81 Kudla, who reached the third round at Wimbledon last year before losing to Novak Djokovic, said: "This is definitely, probably, the biggest win of my career.
"The conditions were super windy, but in the warm-up I felt I was hitting the ball clean."
Kudla will face Australian Jordan Thompson in Sunday's final and added: "There's something about England and grass, I just feel comfortable and at ease. I feel like a different tennis player after being terrible on clay for two months."