Britain's Andy Murray has appointed former world number one Ivan Lendl as his new full-time coach.
Lendl, the winner of eight Grand Slam titles, will start work immediately.
Murray said: "Ivan's impact on the game is unquestionable and he brings experience and knowledge that few others have, particularly in major tournaments."
The Scot won his opening doubles match of 2012, teaming up with Marcos Baghdatis in Brisbane.
Murray and Baghdatis beat Colombia's Santiago Giraldo and Japan's Kei Nishikori 6-2 6-2 at the Brisbane International. He plays his first-round singles match against Mikhail Kukushkin on Tuesday.
Now 51, Lendl is rated as one of the world's greatest players, having won 94 ATP Tour titles in a career that spanned 16 years.
He came from two sets to love down to win the French Open final against John McEnroe in 1984 to claim his first Grand Slam and, after winning the 1985 US Open, he remained as the world's top ranked player for 156 consecutive weeks.
On becoming Murray's coach, Lendl said: "I am really excited to have the opportunity to work with Andy. He is a unique talent and I look forward to trying to help him reach his goals."
Top seed Murray will begin his bid for a 22nd ATP World Tour title at the Brisbane hard court tournament.
The world number four, who is making his debut at the event, said: "It's a tough draw [and] you never know how guys can improve in the off-season.
"There are a lot of good players here and young players as well."
The 2011 Australian Open runner-up is a strong favourite in the men's draw as Roger Federer, Rafael Nadal and Novak Djokovic all miss the event.
But Murray says Australian youngster Bernard Tomic, 19, former Australian Open finalist Marcos Baghdatis and Germany's Tommy Haas are all title threats.
"There are a lot of dangerous players here," the 24-year-old added.
Murray, who struggled with a groin injury in November and had to pull out of the ATP World Tour Finals in London, has already had to dismiss concerns about the recurrence of an old knee injury after having treatment during practice on Friday.
Other notable draws see American Ryan Sweeting take on second-seeded Gilles Simon of France, while 2009 Wimbledon semi-finalist Haas plays Australian wildcard Marinko Matosevic.
Meanwhile in Auckland Britain's second highest ranked woman, Anne Keothavong, won her second round qualifying match at the ASB Classic.
She beat Varvara Lepchenko of the United States 6-3 6-3 to set up a final qualifier against either Jamie Hampton or Irina Falconi.