Canadian rising star Felix Auger-Aliassime's wait for a maiden ATP title was extended on Sunday as the teenager was beaten by Italian Matteo Berrettini in the Stuttgart final.
The 18-year-old has risen to 21st in the world rankings this season, but fell to his third defeat from as many finals, as Berrettini won 6-4, 7-6 (13/11).
The victory in the grass-court Wimbledon warm-up was the 30th-ranked Berrettini's third title, after triumphs on clay in Gstaad last year and Budapest in April.
The Italian won all 50 of his service games in Stuttgart, and didn't face a break point in the final.
"On grass, beating these unbelievable guys... there were a lot of tough moments," said Berrettini, who did not lose a set during his run, ousting second seed Karen Khachanov in the second round.
Auger-Aliassime is one of a number of Canadian youngsters climbing through the tennis ranks, including Denis Shapovalov and Bianca Andreescu.
He saw five set points come and go in the second-set tie-break, before the 23-year-old Berrettini — the first Italian grass-court finalist since Andreas Seppi at Eastbourne in 2011 — took his third match point.