Australian Open: Andy Murray, Roger Federer, Maria Sharapova all in action
Andy Murray is in action, while Roger Federer takes on Jo-Wilfried Tsonga in a re-match of last year's classic.
Last Updated: 19/01/14 12:08pm
The fourth seed will take on Frenchman Stephane Robert, the ultimate surprise package of the first week at Melbourne Park.
The 33-year-old Frenchman lost in the final round of qualifying but gambled by hanging around in Melbourne in the hope that an injury could force one of the main draw to pull out.
His persistence was rewarded when Philipp Kohlschreiber pulled a hamstring while practising on Monday and he has taken full advantage.
World No 119 Robert has won three matches, becoming the first 'lucky loser' to reach the Australian Open fourth round when he beat Martin Klizan of Slovakia 6-0 7-6 6-4 in the third round.
He is already guaranteed the biggest prize of his career - £72,000 - for reaching the last 16.
The pair have never played before but Murray will have to beware a player on a high and with nothing to lose.
Sunday's shock defeat of hot favourite Serena Williams has blown the women's draw wide open and three potential champions open Monday's proceedings on Rod Laver Arena.
Russian third seed Maria Sharapova will expect to come through against Slovakian 20th seed Dominika Cibulkova, but the following match could be a classic.
Sloane Stephens aganist Victoria Azarenka is a repeat of last year's controversial semi-final, when Belorussian Azarenka took a medical timeout after squandering five match points, halting Stephens' momentum at a crucial moment.
The 13th-seeded Stephens is determined to take her revenge against No 2 seed Azarenka, while confirming that their relationship is 'non-existent' despite sharing the same agent.
The pick of the men's matches is the evening contest between 10th seed Jo-Wilfried Tsonga and sixth seed and four-time former champion Roger Federer.
Federer beat Tsonga in five sets in last year's quarter-finals and enjoys a 9-4 career record against the Frenchman, but Tsonga did win their last meeting at Roland Garros in straight sets.