Melbourne, Jan 15 : Canadian tennis sensation Felix Auger-Aliassime showcased his resilience and determination as he quelled a fierce comeback by Dominic Thiem to advance in the Australian Open here on Monday. The 27th-seeded Auger-Aliassime secured a hard-fought 6-3, 7-5, 6-7(5), 5-7, 6-3 victory in a marathon clash that lasted nearly five hours and is now the longest match of his career. Both players entered the match hungry for their first tour-level win of the year, setting the stage for a gripping battle. Auger-Aliassime, who concluded a challenging 2023 season on a positive note with his fifth ATP Tour title in Basel, faced an early setback this year with a straight-sets defeat in Auckland. However, he showcased remarkable resilience and skills in his clash against Thiem. The Canadian talent found himself just two points away from a straight-sets victory, only to encounter a determined Thiem staging a dramatic comeback. Auger-Aliassime, known for his powerful game, had to dig deep and endure a challenging third-set tiebreak where he initially led 5-2 before Thiem turned the tide. Reflecting on the rollercoaster of emotions during the match, Auger-Aliassime expressed a sense of relief. Despite the frustrating moments and the struggle in the third set, he emphasized the importance of mental toughness and maintaining a strong mindset. 'At the end, I didn't want to fail mentally. I didn't want to disappoint myself with my effort or have any regrets when leaving this court today," Auger-Aliassime said. "It was frustrating, the way it went in that third set. I thought, 'You need to be tough, you need to stay strong,' and I'm happy I did because now I'm really happy.' Looking ahead, Auger-Aliassime will face qualifier Hugo Grenier in the second round, who secured his own comeback victory against Alexandre Muller. /IANS