Craig Williams has finished the season in style with a winning double at Caulfield on the day he clinched his fifth Melbourne jockeys' premiership.

Williams went into Saturday's final metropolitan meeting of the 2015/16 season three wins ahead of Dwayne Dunn in the premiership and clinched the title when he guided Hursley to victory in the fifth race.

Dunn got on the board in the sixth race, temporarily keeping slim hopes of a tie alive but that was extinguished a race later.

Williams added his second win for the day - his 70th Melbourne win for the season - aboard the fast-finishing Divine Mr Artie in the eighth event and said it was a great honour to win the premiership again.

Williams won four consecutive titles from 2005/06 to 2008/09, sharing the 2008/09 premiership with Damien Oliver.

"It's a great honour and I've really enjoyed the competition," Williams said.

Williams' premiership charge included five winners in one day at Flemington this month.

"I'm very fortunate a lot of owners and trainers really supported this championship race between Dwayne and I, and Dwayne just rode that well throughout the whole year, he just made me go to another level," Williams said.

"A big thank you has also got to go to my management group and the core group I have around me. They've worked really hard and been very supportive."

Williams said it wasn't smooth sailing heading into the season-ending meeting, revealing his seven-year-old son Oliver had to be taken to hospital early on Saturday morning.

"My wife came in at midnight and said can you ring the emergency and get the ambulance because Oliver has got croup. So he had to go to the hospital, and the medics were brilliant," Williams said.

Williams' wife accompanied Oliver to hospital and the jockey said their son was home six hours later.

"He got his medicine, and then when I left I got to see him and he seemed to be much better," Williams said.

While Dunn said it was disappointing he couldn't make it even more interesting in the final meeting, he acknowledged he had a career-best season.

"It's disappointing that I couldn't have challenged a bit harder for a bit longer but if I could have this season for the next five I'd be stoked," Dunn said.