Day 8 of the Australian Open saw some of the biggest upsets in the tournament. Both Novak Djokovic and Dominic Thiem will now board the plane back home after being ousted from the tournament. Favorites, Simona Halep and Roger Federer are inching closer to the title as they sailed into the quarterfinals of the tournament. Here is all the action from day 8. Former world number one, Novak Djokovic who made a return to tennis after an elbow injury has been ousted from the Australian Open, in one of the biggest upsets of the tournament. 21-year-old, Hyeon Chung, who is currently ranked number 58, outclassed the Serbian 7-6 (7-4), 7-5, 7-6 (7-3) to become the first Korean player to reach last eight of a Grand Slam. Roger Federer's Australian Open title defense is going great as the Swiss maestro eased passed Hungary's Marton Fucsovics with a straight-set victory at the Rod Laver Arena. The 19-time Grand Slam winner won 6-4, 7-6 (7-3), 6-2 to enter the quarter-finals of the tournament. The 36-year-old will now face Czech Tomas Berdych in the last eight Czech Republic's, Thomas Berdych, who is the 19th seed of the tournament, progressed into the last 8 with a comfortable 6-1, 6-4, 6-4 victory over Italian Fabio Fognini. The surprise package of the tournament, world number 97 Tennys Sandgren of the United States staged an upset by ousting fifth seed Dominic Thiem with a 6-2, 4-6, 7-6 (7-4), 6-7 (7-9), 6-3 victory. World number 1, Simona Halep is proving why she is the favorite to win the Australian Open title in a week. The 26-year-old Romanian stormed into the quarter-finals at Melbourne with a commanding victory over Naomi Osaka. Halep, who suffered an ankle injury in the first round of the tournament, showed no signs of pain as she defeated her opponent 6-3, 6-2. 22-year-old, Madison Keys swept aside French eighth seed Caroline Garcia 6-3, 6-2 to book a place in the quarterfinals of the tournament. 2016 champion, Angelique Kerber overcame her tricky opponent Su-Wei Hsieh with a compelling 4-6, 7-5, 6-2 comeback to reach the last 8 of the tournament.