The eighth-seeded Canadian struggled from the start against her 71st-ranked opponent and never really got on track.
Andreescu earned a three-set victory on Monday in her first competitive match in 15 months. But she was unable to generate any momentum against the 35-year-old right-hander.
Hsieh was at her crafty best on a hot, sunny morning in front of a smattering of spectators at Rod Laver Arena.
She consistently worked Andreescu around the court, mixing her shots nicely to keep the Canadian off-balance. Hsieh maintained control throughout the match, completing the victory in one hour 23 minutes.
Andreescu displayed flashes of the championship form that she exhibited in her breakout 2019 season.
She relied primarily on her power game but unforced errors — perhaps a sign of rust from so much time away — were her undoing.
The 20-year-old from Mississauga, Ont., suffered a torn meniscus in her left knee in October 2019. She focused on training last year rather than returning to the WTA Tour once it resumed after a pause due to the pandemic.
Upon arrival in Australia, Andreescu endured a 14-day hard quarantine in her hotel. She declined to play in a warmup tournament last week, electing to focus on practice sessions and training.
Andreescu was one of five Canadian singles players in action on Day 3 of the Grand Slam tournament.
In other second-round matches, No. 19 seed Marketa Vondrousova of the Czech Republic defeated Vancouver qualifier Rebecca Marino 6-1, 7-5.
In men’s play, No. 14 seed Milos Raonic of Thornhill, Ont., was scheduled to play Corentin Moutet of France and No. 11 seed Denis Shapovalov of Richmond Hill, Ont., was to meet Bernard Tomic of Australia.
Felix Auger-Aliassime, the 20th seed from Montreal, was to face Australia’s James Duckworth.
Andreescu started the match with a double-fault and was broken in her first game. Shots were sailing on her and Hsieh was more consistent.
Hsieh displayed great retrieval skills and worked the angles nicely. Andreescu was forced to do more legwork and it seemed to affect her rhythm.
Andreescu gave up another break and started to get more aggressive after dropping her fourth straight game.
The Canadian earned a break of her own to get it to 3-5 but Hsieh served things out, converting her third set point when Andreescu shanked a ground stroke.
Hsieh has a potent game from the backcourt but couldn’t match Andreescu’s power. She relied on other tools and it was effective.
She continued to work Andreescu wide on the court in the second set, dictating the play against the Canadian. Hsieh also wasn’t afraid to go for it, crushing a backhand off a second serve for a winner and break at 4-2.
Andreescu fought off two match points before Hsieh sealed her spot in the third round.