[gallery size="medium" td_select_gallery_slide="slide" ids="31360,31361"] MELBOURNE, AUSTRALIA — Angelique Kerber has upset Serena Williams 6-4, 3-6, 6-4 to win the Australian Open title, ending the six-time champion's unbeaten streak in finals at Melbourne Park. Williams was an overwhelming favorite at the Australian Open, where she had won all six previous times she'd reached the final, and was trying to equal Steffi Graf's Open-era record of 22 Grand Slam singles titles. For the second time in as many majors, though, she fell short. Williams won the Australian Open, French Open and Wimbledon titles in 2015 before losing to Roberta Vinci in the U.S. Open semifinals. The 34-year-old Williams hadn't lost a set in the first six rounds here until dropping the first on Saturday night against No. 7-seeded Kerber, who was playing in her first major final.