The former world No.3 was taking on Australian youngster James McCabe on Saturday, with the Austrian veteran losing the first set 2-6.
But 30-year-old Thiem's plans for a second-set fightback were put on hold when fans courtside spotted a snake.
Australian James McCabe celebrates winning a point against Dominic Thiem in Brisbane. (Darren England/AAP PHOTOS)
Security staff were called in, but the umpire had to temporarily stop play when the snake slithered on to the court.
A snake catcher eventually captured the reptile, which was a 50cm eastern brown snake, and removed it from the venue, allowing play to resume.
Upon returning to play Thiem was down 3-5 but saved three match points to take the second set 7-6 (7-4) and force a decider.
Thiem reached the final of the Australian Open in 2020 when he pushed champion Novak Djokovic to five sets, and won the US Open later that year.
He downed local hope Nick Kyrgios in the third round at Melbourne Park in 2021, but his career went into free-fall due to a troublesome wrist injury and flagging confidence.
Thiem has only reached the second round at a grand slam once since then, making it through the first round at this year's US Open.
His ranking sank outside the top 300, but he has climbed back to world No.98.
Thiem needs to win two matches in qualifying to make it through to the main draw of the Brisbane International.
He is also due to play in qualifying for the Australian Open, having missed the cut-off for the main draw by one place.
