Tennis great Rod Laver and pop princess Kylie Minogue led the tributes to Ashleigh Barty after she won her first Australian Open title on Saturday, with Laver calling her “the complete player”. The 25-year-old kept her cool to rally from 5-1 down in the second set against American Danielle Collins to beat the 27th seed 6-3, 7-6 (7/2) on an expectant Rod Laver Arena. In doing so, the dominant world number one became the first Australian to win her home Grand Slam in 44 years after Chris O’Neil in 1978. The legendary Laver, the only player to win two calendar Grand Slams, was courtside to witnes…