Situations can typically be troublesome on the US Open, which takes place within the New York summer time and frequently has matches performed in oppressive warmth.
This was a type of events. Temperatures hit 35C at Flushing Meadows as Dart confronted Kostyuk within the maelstrom of the mid-afternoon solar.
Each gamers frequently wanted ice towels to chill down and, wanting flustered, struggled to remain composed in an erratic match which lacked high quality.
Double faults have been thrown round frequently from every server, together with one by Kostyuk on a set level within the tie-break, with one other from Dart additionally handing over the primary break of the second set.
Wild returning was one other function of a match which, notably within the first set, was a troublesome watch.
Dart will turn into the British quantity two after the US Open, climbing above Emma Raducanu, when she rises the rankings on the again of her first-round victory over France’s Chloe Paquet.
Beating Kostyuk would have moved Dart into the highest 60 and secured one of many greatest wins of her profession by rating.
She made a pointy begin however was left to rue not being scientific sufficient in a scrappy first set and punishing Kostyuk, whose piercing roar at securing the lead indicated her personal angst.
A suspect second serve has been one thing which Dart’s opponents have pounced on. Right here, she punished herself with the quantity of double faults.
Touchdown 46% of first serves within the match and profitable simply 28% of second-serve factors, additionally starkly illustrated the place the issues lie.
Dart appeared near tears initially of the second set and continued to gesticulate in the direction of her staff, which was led by mum Susie who has been teaching her in New York.
Reassuring phrases couldn’t assist a demoralised Dart settle again into her rhythm and the combat was sucked out of her.
Kostyuk, who had performed far beneath her rating, instantly relaxed on account of her opponent’s issues and wrapped up a victory which was extra snug than it ought to have been.