Emma Raducanu dug deep to grind out a marathon straight-sets victory over Peyton Stearns to progress at the Korea Open on Tuesday.
The Brit, who reached the semi-finals in 2022, needed two tie-breaks to win, holding off Stearns 7-6 (7-4) 7-6 (7-5) in two hours and 46 minutes.
The play was delayed for 45 minutes due to excessive heat before the pair traded breaks in the opening three games, with Raducanu at one point holding a 4-1 lead before Stearns fought back to force the first tie-break.
Raducanu prevailed but was put straight back under pressure in a lengthy opening game of the second set, saving break point three times to get off the mark.
There was little to separate the two throughout though, as they continued to trade breaks before the 2021 US Open champion found her edge again to take the tie-break.
She will face last year's Korea Open runner-up Yuan Yue in the next round.
Data Debrief: Going the distance
Raducanu was playing her first match since being knocked out of the US Open, and she was certainly made to work for the victory.
It featured a combined tally of 28 break points and 12 breaks of serve, with eight of those coming in a topsy-turvy first set.
Raducanu successfully saved nine of 15 break points compared to seven of 13 for Stearns.