Family members have watched on with pride as Craig Williams claimed the Melbourne Cup to complete a career 'grand slam' in Australian racing.

Williams famously missed the winning Melbourne Cup ride on Dunaden in 2011 because of suspension, having already ridden the winners of the Caulfield Cup and Cox Plate that spring.

His narrow win on Vow And Declare in Tuesday's race gave Williams the Cup he craved to go along with two Caulfield Cups, two Cox Plates and a Golden Slipper.

"That's awesome. I'm speechless," Williams' brother Jason Williams said.

"It's a dream come true for him. He's worked so hard from the time he's been an apprentice.

"To see what he went though a number of years ago with Dunaden and to come back from that, it's just been a marvellous effort.

"He's got a lot of good people around him."

He said he turned to Williams' manager Jason Breen before the horses reached the home turn of Tuesday's race and told him Williams had given Vow And Declare a "perfect trail" and only needed luck from there to be hard to run down.

"The leader fanned and he got up along the fence but it was a tactically brilliant ride," he said.

"No-one expected him to go forward like that but that's why he's been so successful. It's those little one per centers that count."

He said his overwhelming emotion was pride.

Williams' father Allan, a former jockey and now trainer in partnership with Jason, also said it was a proud moment but there was another emotion too.

"I was relieved for him. That he finally did it," he said.

"It was only a short margin. So it could have gone either way. I actually thought he had won when he crossed the line. I thought his head was down, but it was close.

"I didn't barrack that much during the race, there were enough around me doing that. But I was just hoping he would get there and he did. I'm very pleased for him."

Williams' father said his son had worked hard right from the time he was a "fat little kid" starting out, and was always hoping he would get the elusive Cup, something he's achieved at the 16th attempt.

"He's worked really hard so good on him," he said.