British number one Katie Boulter won the biggest title of her career to date as she came from a set down to sink Ukraine's Marta Kostyuk and become San Diego Open champion.
The 27-year-old capped off a week of stellar displays with a 5-7 6-2 6-2 comeback success over Kostyuk in two hours and 13 minutes, clinching her maiden WTA 500 honour in the process.
Boulter's second WTA Tour triumph also represented her first tournament success on hard courts, having only won her inaugural title at last year's Nottingham Open on grass by beating compatriot Jodie Burrage in the final.
Thanks to her success in San Diego, Boulter has surged to a career-high ranking of 27 - up 22 places from starting the week at world number 49 - and she is just the second British woman to win a WTA 500 crown after Johanna Konta.
"I don't know what just happened," Boulter said during her victory speech. "This week has been very, very special for so many different reasons. This one is pretty amazing, I've worked very hard for it, I played some incredible tennis all week.
"Today was a complete battle, with myself as well, because I was a little bit nervous. But I managed to get over the line, and that I'm very proud of.
Superb in San Diego 😤@katiecboulter outlasts Kostyuk in three to claim the title!#SanDiegoOpen pic.twitter.com/aE1M7oBgHn
— wta (@WTA) March 4, 2024
"A lot of it was about me staying as tough as I possibly could mentally, and I managed to keep my cool and actually kind of went within myself and calmed myself down a lot. I think that really helped me, and then I started to relax and play through shots a little bit more."
Boulter had sent Emma Navarro, Donna Vekic, Beatriz Haddad Maia and Lesia Tsurenko packing to reach the showpiece match, where she would clash with 2024 Australian Open quarter-finalist Kostyuk for the first time at the highest level.
The British number one made her first WTA 500 final despite racking up 28 double faults in her previous four contests - an average of seven per match - and she committed another 13 such errors in Sunday's trophy battle.
Six of those double faults came in the opener, although Boulter still broke Kostyuk back while she was serving for the set and proceeded to save five set points, but the Ukrainian made no mistake on her sixth.
Boulter had only dropped one set en route to the final against Haddad Maia, but her powers of recovery were too hot for Kostyuk to handle in the second set, where she roared her way to three breaks of serve and converted her second set point to level the match.
The clinical 27-year-old required just two break points to earn two breaks in the title-deciding set, and after bringing up her first Championship point, Boulter fizzed an excellent forehand beyond Kostyuk's reach to etch her name onto the trophy.
In attendance to watch Boulter win the title was her boyfriend Alex de Minaur, who had defended his Mexican Open title just hours before travelling to San Diego, overcoming Casper Ruud 6-4 6-4 in the final after Jack Draper retired from their semi-final due to illness.