Ukrainian Marta Kostyuk lifted her first WTA singles trophy after defeating Russia's Varvara Gracheva 6-3 7-5 in Sunday's ATX Open final.

Kostyuk only needed to beat one seeded opponent en route to the title, eliminating fourth seed Danielle Collins in the semi-final to set up a showdown against the 22-year-old ranked 88th in the world.

In an incredibly back-and-forth first set, eight of the nine games went against serve, including five consecutive breaks to begin the match, with the 20-year-old Kostyuk's lone hold good enough to take the lead.

With both players competing in their first final at this level, the nerves were apparent, as they combined for eight double faults in the opening set and another six in the second.

It was Gracheva pulling ahead 5-3 as she tried to force a decider, but after saving a set point, Kostyuk broke back to make it 5-5, and rattled off the final four games of the match to claim the title.

Coming into the tournament ranked 52nd in the world, Kostyuk will surpass her career-best mark of 45th when the next set of rankings are released.