WATCH Barty in the China Open final LIVE & EXCLUSIVE in Australia on beIN 3 & CONNECT at 7.30pm Sunday
Having come from a set down to win a tough quarter-final against Petra Kvitova, Barty was again tested by the eighth-ranked Dutch star, saving a match point to advance to her fifth final of the WTA season.
After racing to a 6-3 first set lead, Barty lost the second 3-6, before winning a tie break in the third 9-7, to set up a final against either Caroline Wozniacki or Naomi Osaka, both of whom play their semi-final at 9.30pm.
Among the biggest improvements to Barty's game in this, her break-out year on tour, has been her serve. She fired down nine aces to Bertens' five, winning a commanding 72 percent of her points on the first serve.
In the tense, final set, the match went down to the wire, the Australian prevailing to advance to her fifth final of the season, including her grand slam breakthrough win at the French Open in June.