Dayana Yastremska in action during her semi-final match against Magda Linette at True Arena Hua Hin.

Ajla Tomljanovic will battle it out against Dayana Yastremska in the final of the US$250,000 WTA Thailand Open at True Arena Hua Hin on Sunday.

The sixth seed and world No.49 Tomljanovic of Australia cruised past unseeded Tamara Zidansek of Slovenia 6-4, 6-1 in the semi-finals on Saturday to advance to her fourth career WTA singles final.

Ukrainian teenager Yastremska, who fended off a challenge from unseeded Magda Linette of Poland 6-4, 6-3 in the second semi-final, will play for her second career WTA title in six months. She won her first in Hong Kong last September.

It was Yastremska's second win in two meetings against Linette. The 18-year-old rising star also won their first match-up at the 2018 Connecticut Open 7-6 (7/3), 7-6 (7/4).

Eighth seed Yastremska, who has not dropped a set all week, knocked out top seed and two-time Grand Slam champion Garbine Muguruza 7-6 (7/5), 6-1 in Friday's quarter-finals -- her second win in a span of four months against the former world No.1 from Spain.

Yastremska became the first woman born in the 2000s to crack the top 100 in the WTA rankings, reaching No.100 in July last year. She is currently ranked 47th in the world.

Tomljanovic, who also has not dropped a set, continued her remarkable run in Hua Hin by losing just five games against the Slovenian No.1.

The 25-year-old Aussie broke in the first game of each set and never trailed during her one hour and 39 minutes stay on court, never even facing a break point on serve until what proved to be the penultimate game of the match.

Tomljanovic won the first four games of the second set to gain some breathing room after a tight opener, in which she built an early lead and had all the answers to any challenge from Zidansek.

She lost just six points behind her serve overall, winning 81 percent of the points when she landed her first serve, and won four of eight break points she earned in the match.

The match was the third meeting between the two players, with Tomljanovic now leading 2-1 in their head-to-head record.

Earlier, second seeds Irina-Camelia Begu and Monica Niculescu of Romania beat Han Xinyun of China and Darija Jurak of Croatia 7-6 (7/4), 6-2 to advance to the doubles final.

They will play another unseeded pair Anna Blinkova of Russia and Wang Yafan of China in the decider.