Liu, who entered the WTA 250 event ranked 102nd in the world, added the SAR trophy to a cabinet which already includes challenger-level titles she won in Paris in 2022 and Barranquilla in September this year.
The pair found themselves locked in a fierce battle at Victoria Park early on, trading blistering shots to go level at 3-3 in the opening set.
After the second-seeded Eala received medical treatment on her right knee, Liu began to pull away convincingly, capitalising on costly errors from her opponent to claim the opener in 38 minutes while overcoming a strong show of support from Filipino fans in the crowd.
The second set proved to be a far more straightforward affair, with Liu breaking serves and wearing out a visibly shaken-up Eala to take the title in dominant fashion.
Defeat denied a second major career title for Eala, who was bidding to add to her historic triumph in Washington DC in August that saw her become the first Filipina player to reach and win a WTA 500 final.
In the doubles final, Japan’s Miyu Kato and Chinese Taipei’s Chan Hao-Ching claimed the title, beating Talia Gibson and Maddison Inglis of Australia 6-4, 6-4.