NEW YORK (Reuters) - Canadian Denis Shapovalov says a lack of maturity cost him a semi-final berth at the U.S. Open, a Grand Slam that is up for grabs in the absence of the 'Big Three' of men's tennis.
The 21-year-old went down in five sets to Pablo Carreno Busta on Tuesday in a match he looked destined to win after serving his opponent a bagel in the fourth set and then watching him receive treatment to his lower back before the decider.
With Roger Federer and Rafa Nadal absent from Flushing Meadows, and Novak Djokovic disqualified in the fourth round, there will be a new name on a Grand Slam trophy for the first time since Stan Wawrinka's 2016 U.S. Open triumph.
"Very frustrating right now. Tough to look at positives," left-hander Shapovalov told reporters. "I need to mature a little bit more, be in these situations more often.
"I played tight, I did. I'm sure the next time I'll be in this situation I'll be more comfortable with it."
Shapovalov had been in long battles in earlier rounds, facing a match point in his third-round win against Taylor Fritz and being pushed to four sets in his three other matches before Tuesday's quarter-final -- his first at a Grand Slam.
"Definitely physically speaking I feel good. I feel like I could go all the way," he said. "That's a positive. I found a positive."
With Carreno Busta, Alexander Zverev, Dominic Thiem, Alex de Minaur and Russians Daniil Medvedev and Andrey Rublev still in the hunt for the trophy on Sunday, Shapovalov said few of them will have experienced the pressure of a deep Grand Slam run.
"There's a lot of dark horses out there. It's anybody's slam," he added.
"It's very exciting for tennis. It's definitely causing a lot of nervous matches."
(Reporting by Sudipto Ganguly in Mumbai; editing by Peter Rutherford)