Belgians secured a trophy double at the Kooyong Classic on a rainy Friday as David Goffin was crowned champion for the second-straight year and Yanina Wickmayer joined him as a title winner.

The 11th-ranked Goffin backed up his 2016 trophy, winning a final reduced to one set 7-6 (7/2) over Ivo Karlovic on a day of rain interruptions.

Wickmayer beat Romanian Sorana Cirstea 6-4, with both finals shortened to get play completed. Women were competing at the Australian Open tune-up for the first time in more than two decades.

Goffin and the giant Croatian serving machine Ivo Karlovic got their delayed final underway later in the afternoon, with the winner overcoming 10 aces from his towering opponent, who stands well over two metres.

The four-day hit-out at the former home of the major has long been a staple of the week prior to the start of the Grand Slam, with organisers known for making some of their own rules on the fly in order to get play on court.

It took a courtside visit from tournament director Peter Johnston to ensure that Goffin and Karlovic played a normal tiebreaker to end the set when that point momentarily became one of confusion to players and the chair.

Goffin won through his precision returns on a court which the players feared was still slippery from moisture.

"It's never easy to wait when it is raining and finally we played a set," Goffin said.

"So it was nice to play some tennis today and against Ivo it's always the story of tiebreaks.

"It was a funny tiebreak (he led 5-0) and it was nice for the crowd, for the people who stayed all day long just to give them some tennis.

"I'm feeling ready for the Open and that's the most important thing."

Earlier, Frenchman Gilles Simon got what he described as a taste of home as he overcame drizzle to defeat Bernard Tomic for a third-place finish.

In a contest also played over one set, he won 6-3.

"This is close to French weather so I'm used to it," the 25th-ranked Simon said after his 26-minute win, which left Australia's Tomic without a victory this year heading into Monday's Australian Open start.

"The conditions were tough, but things change so much here. We know in two days it will be 35 Celsius (95 Fahrenheit) again.

"I'm feeling fine for the Open even if I did not play a lot of matches before," he added.

Simon, 32, will start at the Grand Slam against American teenager Michael Mmoh.

"I saw him at the US Open," Simon said, joking: "At my age, there are no good draws. I will try to take him down if I can."

Defeat left Tomic winless since late September in Shenzhen, China.

"It was a shame the rain started the last two games but it's quality for me and him, and we're both ready to play on Monday," Tomic said.

Source: AFP