Boulter dominated Ukrainian Kostyuk to secure a victory that lifts her to a career-high ranking of 27th in the world.

Katie Boulter won her first WTA 500 title by fighting back from a set down to defeat Marta Kostyuk in the San Diego Open final. The 27-year-old Briton won 5-7 6-2 6-2 in the biggest triumph of her career so far.