Hua Hin, 3 February 2019 | AAP

Ajla Tomljanovic beat Slovenia’s Tamara Zidansek 6-4 6-1 at the Thailand Open to reach her fourth WTA final.

Chasing her first title, sixth seed Tomljanovic on Sunday faces 18-year-old Dayana Yastremska of Ukraine, who beat Magda Linette of Poland 6-4 6-3 in the other semifinal.

“It was a bit scrappy in the first set but I managed to clean it up in the second,” Tomljanovic said.

The world No.49 also reached the final in 2015 when it was held in Pattaya, losing to Daniela Hantuchova.

The Australian lost finals at Rabat and Seoul last year.

“I have to play the best match out of five years to win,” the 25-year-old said.

“I’m excited to have another opportunity to win my first title. I don’t enjoy losing in the final.”

Tomljanovic broke right from the start and held on to lead 5-3.

She trailed 30-0 serving for the set but delivered four powerful serves to take the opener in 40 minutes.

Tomljanovic then dominated the second set with a powerful baseline game.

Yastremska’s match against Linette was suspended for 10 minutes by light rain at 3-3 in the first set.

When play resumed, both players held serve until the 10th game, when Yastremska powered a forehand service return winner to take the set.

Eighth seed Yastremska hit 29 winners against Linette as she reached her second final after winning in Hong Kong in September.

“It was not easy as we had to stop due to unpredictable weather,” Yastremska said.

“I had to hit winners as she was consistent at the baseline. I will try to hit like this tomorrow.”