Melbourne, January 14 World number ones Novak Djokovic and Serena Williams were named the top seeds on Thursday for next week’s Australian Open with organisers aligning with the current rankings. Djokovic is chasing his sixth title after beating Andy Murray in last year’s final, while Williams, battling a knee injury, is after her seventh Australian crown. Murray, who has lost in four Australian finals, three of them to Djokovic, is the second seed ahead of 17-time Grand Slam champion Roger Federer. Fellow Swiss Stan Wawrinka, who won in Melbourne in 2014, is the fourth seed with Rafael Nadal at five. French world No 9 Richard Gasquet was not among the seedings for the year’s opening Grand Slam because of a back injury. Romania’s Simona Halep is the second seed in the bottom half of the women’s draw ahead of Spain’s Garbine Muguruza and Poland’s Agnieszka Radwanska. Maria Sharapova is fifth seed, while Victoria Azarenka of Belarus is seeded at 14. Italy’s Flavia Pennetta, ranked at eight, retired from the sport after last year’s US Open. The 2016 Australian Open runs from January 18-31.