MELBOURNE, Australia (AP) -- The opening Grand Slam tournament of the year ended Sunday with Novak Djokovic winning his fifth Australian Open title and denying Andy Murray his first. Outside of a few days when the temperatures topped 30 degrees Celsius (86 degrees Fahrenheit) in the first week, the searing hot temperatures that can often affect play at the tournament were not an issue this year. It was also two weeks of record attendance - 703,899, breaking the previous mark of 686,006 in 2012 - due in part to a new roof on Margaret Court Arena, giving Melbourne Park three stadiums with retractable roofs. Here are some things we learned from the 103rd edition of the Australian Open: --- TOUGH AT THE TOP: Novak Djokovic and Serena Williams extended their impressive records in finals at the Australian Open, where the No. 1 seeds in the men's and women's draws clinched the titles. Williams has won all six singles finals she has contested at the Australian Open, and Djokovic maintained his 100 percent record in five finals. It was another disappointment Down Under for Murray, who has lost four Australian Open finals in six years, including three defeats to Djokovic. ---- BIG FOUR RESTORED: Andy Murray moved into fourth place in the ATP rankings, despite his loss to Djokovic in the final, restoring the so-called Big Four. Djokovic remains at No. 1, followed by Roger Federer and Rafael Nadal. That's a combined total of 41 Grand Slam singles titles - Federer has 17, Nadal 14, Djokovic eight and Murray two. The men frequently touted as challenging the Big Four for Grand Slam titles in the future will have to wait for another major - U.S. Open finalist Kei Nishikori and Wimbledon semifinalist Milos Raonic lost in the quarterfinals and Grigor Dimitrov went out in the fourth round. ---- SERENA VS. SHARAPOVA: Maria Sharapova lost her 16th consecutive match to Serena Williams, who won her 19th Grand Slam singles title in the straight-sets Australian Open final to move closer to Steffi Graf's Open-era total of 22. No. 2-ranked Sharapova was gracious in defeat. ''I haven't beaten her in a long time but I love every time I step on the court with her,'' said Sharapova, who trails 17-2 in career head-to-heads and hasn't beaten Williams since 2004. ''I've had some of the best memories of my career on this court and also some of my toughest losses, but that's the life of a tennis player.'' Her best memory of any match against Williams was her first major - Wimbledon in 2004 - when she beat the American in straight sets in only their second career meeting. --- KEYS AND THE AMERICANS: Madison Keys, a 19-year-old rising star, had a breakthrough tournament, beating Wimbledon champion Petra Kvitova in the third round and fellow Americans Madison Brengle and Venus Williams in the fourth round and quarterfinals before losing to Serena Williams in the semis. Four American women reached the round of 16, a good start for the U.S. contingent in the first major of the year, particularly the return to the quarterfinals of Venus Williams after an energy-sapping illness affected her play for more than four years. --- THE CONTROVERSIES: An on-court presenter asked 20-year-old Eugenie Bouchard of Canada to ''give us a twirl,'' to show off her dress, which soon became known as ''Twirlgate.'' Andy Murray's fiancee Kim Sears mouthing obscenities from the player box during the Scotsman's fiery win over Tomas Berdych (who hired Murray's former coach) in the semifinals. At Sundays' final, Sears poked fun at herself by wearing a t-shirt which said: ''Parental Advisory Explicit Content.'' And she appeared to behave herself, unlike two political protesters who were arrested after a court invasion during the men's final. Play was delayed in the second set after a protester was grabbed by a security guard at the back of the court. Organizers said police were expected to lay charges Monday. --- MAJOR MARTINA: Martina Hingis won her first Grand Slam singles title at the Australian Open in 1997, and the 34-year-old Swiss player added her 16th of all varieties when she combined with India's Leander Paes to take the mixed doubles title at Melbourne Park on Sunday. Hingis, who won the 1997 Wimbledon and U.S. Open singles titles, also won the Australian Open in 1998 and 1999 for a trio of singles titles at Melbourne Park. She has nine Grand Slam women's doubles titles, including four in Australia, where she has now won the mixed doubles twice. ''I never thought I would be standing here nearly 20 years later,'' Hingis said during the trophy presentations.