Grace Brown has fittingly closed her cycling career with another win, capping a dream swansong season.

The Australian took out the Chrono des Nations time trial for the first time, beating FDJ-Suez teammate Vittoria Guazzini by 51 seconds over the 27.2km event in France.

"It's done ... it's time for the rest of life," Brown said in an Instagram video post from her team.

The 32-year-old will return to Melbourne in the next few days, with a bulging trophy cabinet to enjoy.

The time trial specialist won Australia's first gold medal at the Olympics, taking out the event in sodden conditions on day one of the Games.

It was Brown's first Olympic medal.

Brown had started the year in January by winning her third-straight Australian time trial championship - the fourth time overall she had claimed the title - despite a back injury.

In April she had the biggest road race win of her career, claiming the Liege-Bastogne-Liege classic.

Two months later, with Paris looming, Brown stunned the sport by announcing this season would be her last.

Brown explained in an emotional video post that she missed her Australian life.

There were plenty of queries after her Paris gold medal about whether Brown would revisit that decision, and those questions only multiplied after the Australian starred last month at the world road championships.

Brown won her first time trial world title and then was part of the Australian team that claimed the mixed team relay, also for the first time.

In May, Brown also won the Bretagne Tour in France for the second-straight year.

Brown ends her professional cycling career with 26 wins - and the top highlights all this season.