Thanasi Kokkinakis has watched nine break points sail him by in the decisive set to end the local hope's Adelaide International 2 title defence.
The Australia threw his biggest punches at Memorial Drive but the craft and nerve of veteran Roberto Bautista Agut proved too much in a 7-6 (7-4) 3-6 6-3 semi-final loss on Friday night.
Kokkinakis looked to have finally cracked the 34-year-old's defence early in the third set, having earlier blazed a flurry of forehands past the world No.26 to level the match.
The Spaniard's armour held firm though, Bautista Agut saving three break points in his first service game and five more in his third.
He broke a distracted Kokkinakis for the first and only time in the match in between, the Australian briefly rattled after an incredible drop shot while back pedalling saved one of those eight chances to break.
Bautista Agut saved another break point while serving out the match, Kokkinikas successful from just one of 12 of those crucial moments in total.
"He's a very good player, serving unreal and very good on this court," Bautista Agut said of Kokkinakis as his son ran on court to congratulate him.
"He's a great potential and it's very tough to beat Thanasi on this court today."
A maiden winner at last year's Adelaide event, Kokkinakis will at least have an extra day's rest before a tricky first-round Australian Open clash with Italian danger Fabio Fognini.
He'll carry formidable form in too, the world No.110 beating No.6 Andrey Rublev and the 28th-ranked Miomir Kecmanovic on his way to the final four.
Any wins at the Australian Open will provide a rankings boost for Kokkinakis, who fell meekly in the first round last year after an emotional run to his home title.
Bautista Agut will play his 22nd ATP final against surprise packet Soonwoo Kwon in Saturday's Adelaide final after the South Korean blasted young British star Jack Draper off the court earlier in the day.
Into the main draw as a replacement after losing in qualifying, the South Korean world No.84 withstood the sapping Adelaide heat to prevail 7-6 (8-6) 6-7 (2-7) 6-3 in two hours 45 minutes.
Comfortably beaten by world No.40 Draper in Adelaide last week, Kwon went on the offensive to turn the tables.
He crushed a brilliant cross-court forehand winner to claim a tense first-set tie break and then, after dropping the second set, kept firing in the third.
His second break of serve secured the match, Kwon hitting 48 winners in total as he sets his sights on a second ATP title.
Draper will turn his attention to Monday's first-round clash with Australian Open top seed and defending champion Rafael Nadal.