Nicknamed "The Wizard", he won the premier event 2012 European Championship, and the 2022 World Cup of Darts for Australia, partnering Damon Heta.

In 2003, Whitlock reached the last 16 of the World Championship, with wins over Paul Williams and Peter Manley, but lost to Richie Burnett 5–3.

[1] In other major events, he also reached the semi-finals of the International Darts League in both 2005 and 2006, losing to Mervyn King and Raymond van Barneveld respectively.

Whitlock competed in the BDO World Championship, achieving wins over Edwin Max, Fabian Roosenbrand, Ted Hankey, and Brian Woods to reach the final, where he lost to Mark Webster 7–5.

[2] Whitlock entered the 2009 BDO World Darts Championship as the number twelve seed and reached the second round, defeating Mark Barilli, but losing to Darryl Fitton.

He qualified for the Las Vegas Desert Classic but lost in the first round of the televised stages against Terry Jenkins.

At the 2009 Grand Slam of Darts Whitlock won all 3 of his group stage games with wins over Ted Hankey, Wayne Mardle and Scott Waites.

At the 2010 PDC World Championship, Whitlock defeated Colin Osborne, Wayne Jones, Terry Jenkins, James Wade, and Raymond van Barneveld before losing to Phil Taylor 7–3.

[6] After his run to the World Championship final, it was announced that he would be competing in the 2010 Premier League Darts as a wild card.

At the 2010 Grand Slam of Darts, he lost all three of his group matches against Dave Chisnall, Colin Osborne and Robert Thornton.

Whitlock represented Australia alongside Paul Nicholson during the inaugural PDC World Cup of Darts in December 2010, losing out in the semi-finals to Wales' Mark Webster and Barrie Bates.

At the 2011 PDC World Darts Championship, Whitlock defeated Steve Evans and Denis Ovens before losing to Vincent van der Voort in the third round.

Together they achieved victories over Ireland, Belgium and the Netherlands to final, where they played the England's Phil Taylor and Adrian Lewis.

[20] Whitlock hit a nine-darter in his second round match at the 2012 Austrian Darts Open (ET1) against Joe Cullen, but lost 6–4.

[24] Whitlock then won his first European Tour title at the 2012 Dutch Darts Masters, defeating his World Cup partner Paul Nicholson 6–1 in the final.

[45] Whitlock and Nicholson reached the semi-finals of the 2014 PDC World Cup of Darts where they faced England's Phil Taylor and Adrian Lewis.

[48] At the World Matchplay, Whitlock recorded wins over Kevin Painter, Raymond van Barneveld and James Wade to reach the semi-finals of the event for the second time.