Jack Draper missed out on a place in his first ATP Tour singles final as he lost in three sets to Kwon Soon-woo in the semi-finals of the Adelaide International 2.
Despite easing past the South Korean 6-2 6-1 in the Adelaide International 1 last week, Draper fell to a 6-7 7-6 3-6 loss in two hours and 45 minutes this time around.
A masterclass in serving from both men saw 31 aces fired throughout the match - 18 of which were from Draper - but untimely double faults also proved significant for the world number 40.
Kwon broke Draper for a 6-5 lead in the first set before the Briton earned the break back to force a tie-breaker, which the South Korean edged before finding himself 40-0 down on serve in the third game of the second set.
Kwon faced five break points and hit three double faults in that game alone, but he remarkably managed to survive before Draper dominated the next tie-breaker, storming into a 6-1 lead and taking the match to a third set.
However, the 21-year-old crucially double-faulted twice in the opening game as Kwon broke right off the bat, and he would not relinquish that lead, breaking one final time in the ninth game with four winners to advance to the final.
Kwon will meet either Roberto Bautista Agut or Thanasi Kokkinakis in the showpiece event, as Draper now prepares for his Australian Open first-round battle with 22-time Grand Slam winner Rafael Nadal next week.
However, British number one Cameron Norrie advanced to the final of the ASB Classic earlier on Friday, defeating Jenson Brooksby 6-3 6-4, and he will compete for his fifth ATP Tour singles title against France's Richard Gasquet on Saturday.