World number seven Marin Cilic tested a knee injury with the best possible result on Wednesday, but temperamental Nick Kyrgios' poor start to the season continued at the Kooyong Classic.
Former US Open champion Cilic, who led Croatia to a Davis Cup trophy in November, skipped last week's Maharashtra ATP tournament to rest.
The wait was worth it as he posted a gritty 6-3, 4-6, 15-13 win over Kevin Anderson, recovering from 2-7 down in the new final-set tiebreaker that will be used at the Australian Open for the first time next week.
Under the rules, the first player to win at least 10 points by a two-point margin takes the match.
Kyrgios, who was knocked out in the second round at Brisbane last week, was beaten 6-3, 6-4 by friend and fellow comeback candidate Bernard Tomic in an all-Australian battle.
Tomic ended his victory with a flourish, sending over a sneaky serve on match point by hitting the ball between his legs for a winner — a move which totally caught Kyrgios off guard.
"It was a lot of fun just to get back out there," the often edgy Kyrgios, who has slipped to 51 in the world, said.