Daniil Medvedev will play Kei Nishikori in the Brisbane International final after the Russian's clever serving proved too much for tiring Frenchman Jo-Wilfried Tsonga.
The 22-year-old lost just 10 points on serve all match - at one stage winning 17 straight points on his delivery - in a 7-6 (8-6) 6-2 win on Saturday.
But the world No.16 almost let the first set slip as Tsonga twice rallied from 0-40 down to hold serve and then shoot to a 4-1 lead in the tiebreaker.
That became 6-4 before Medvedev won the next four points to claim the set.
Tsonga, on the comeback from knee surgery that saw him miss seven months of last year's tour, couldn't touch the Russian in the second set as the match wrapped up in 84 minutes.
Medvedev's finals appearances builds again on his breakout 2018 season, in which he won more matches on hard courts (38) than any other man on tour.
Second seed Nishikori was equally impressive in his 6-2 6-2 defeat of Jeremy Chardy earlier in the day.
The pair having split their two previous career meetings one-all, while Nishikori is chasing his first title in nearly three years.
