Serena mistakenly enters court on 'Welcome, world no.1' announcement
Ex-world number one Serena Williams, who is currently ranked 16, mistakenly entered the court after the announcement "Please welcome to the court, world no.1..." was made for her opponent Simona Halep ahead of their Australian Open fourth-round clash. Serena, wearing large headphones, realised her mistake and returned to the tunnel before Halep entered the court, amid laughter from the crowd.