American Sofia Kenin fulfilled her potential by winning a first Grand Slam title with victory over Spain's Garbine Muguruza at the Australian Open.Kenin won 4-6 6-2 6-2 against two-time major winner Muguruza in Melbourne.The 21-year-old was a child prodigy, who started making television appearances from the age of five and hitting with the stars soon after."My dream has officially come true," said Kenin, the eighth first-time women's champion in the past 12 Slams."Dreams come true. If you have a dream then go for it - it will come true."These two weeks have been the best two weeks of my life."Kenin, who turned 21 in November, is the youngest Australian Open champion since Russian Maria Sharapova in 2008.The American 14th seed was gifted victory when Muguruza produced a double fault on the second match point - the Spaniard's third of the game and eighth of the match.Kenin dropped her racquet to the court and covered her face in shock, before going over to the opposite corner where her dad - and coach - Alex was sitting.The pair warmly cupped hands before she returned to the court, spinning around and lifting her arms up towards him again in a gesture which summed up her shock.