After Jannik Sinner's Australian Open victory, Maria Sharapova took to Twitter, celebrating with a unique touch. She shared a video of them singing 'Deck the Halls,' donning reindeer headbands. Maria, hinting at a shared history, wrote, "I knew that one day you'll regret this. Congrats Champ!!" Her heartfelt message praised Jannik's patience, poise, and class.