Janice Tjen is the first Indonesian woman since Angelique Widjaja in 2002 to win a WTA Tour singles crown.
Jannik Sinner was in ominous form on the Rod Laver Arena court he has ruled for two years before the match was cut short.
Backed by passionate Turkish fans, Zeynep Sonmez defeated Anna Bondar to reach the Australian Open third round and match her best Grand Slam run.
Players from the Philippines and Hong Kong will be on the schedule for the second round of a Grand Slam for the first time this week, as the U.S. Open sees the impact of an increasingly global game.
Filipino Eala and Indonesia's Tjen round-off historic day for Southeast Asia with first round wins in their respective matches at Flushing Meadows on Sunday.
Former champion Emma Raducanu claimed her first victory at the tournament since lifting the trophy in 2021 by beating Japan's Ena Shibahara in the first round on Sunday.
Carlos Alcaraz demolished Mattia Bellucci to banish memories of last year's shock early exit at the US Open on Wednesday.
IMAGES from Day 1 of the US Open matches played at Flushing Meadows, New York on Sunday.