West Indies captain Kraigg Brathwaite couldn't help but chuckle when reflecting on the "brain fade" moment that almost cost him his wicket while celebrating a fighting century against Australia.

Brathwaite dropped his bat while completing the single that brought up his ton in the first Test against Australia in Perth on Saturday.

Instead of waiting for the ball to go dead, Brathwaite casually walked back to the middle of the pitch to pick up his bat - before realising the ball was still live.

Brathwaite abandoned his mission to pick up the bat and quickly scrambled back before the ball made it to Nathan Lyon at the non-striker's end.

The umpire then gave Brathwaite permission to pick up his bat, and the star opener duly celebrated.

"I guess that was a bit of a brain fade to be honest," said Brathwaite, who was unbeaten on 101 at stumps.

"The ball wasn't dead, so I don't know where I was going. Thankfully it didn't cost my wicket.

"For me it (the century) means everything.

"Growing up as a youngster watching the West Indies play - Viv Richards, Desmond Haynes and Brian Lara - you know Australia is going to be a tough place for batting.

"Australia is No.1, so this century is up there (in my career highlights)."

Brathwaite received a slice of luck along the way, with a Josh Hazlewood delivery clipping his bail when he was on 67.

The bail stayed on, and Brathwaite made the most of the lucky escape.

"I saw it on the big screen. I was just thankful for my luck," he said.

Remarkably, of the last 11 centuries by a West Indies opener, Brathwaite has scored all of them.

He now holds the key to the West Indies' hopes of salvaging a draw or pulling off a remarkable victory against Australia.

The West Indies will resume at 3-192 on the final day chasing 498 for victory.

"It's not going to be easy, but I'm going to go out there and fight for the West Indies," he said.