Navarro had seemingly sunk his teeth into the competition after winning four straight matches by one set and 0-2. But Birrell managed to come back on serve, putting the match on her racket thanks in part to the backhand shots she sent across the net.
Even though the wild card wasn't able to serve out the matchup, Navarro didn't turn the opportunity into a significant momentum shift. Birrell, who was leading his opponent's second serve for much of the day, hit an inside-out forehand winner to break love. The 26-year-old ultimately finished with the final eight points to reach the round of 16.
In her first round, Birrell defeated compatriot Priscilla Hon, 2-6, 7-5, 6-2. The current No. 113 is within reach of her career-high of No. 100 after notching two victories in the main draw of the 500-level tournament.
For Navarro, her 2025 debut contrasts with last year when she opened her season by qualifying for the semi-finals of the ASB Classic in Auckland.