Dylan Gibbons has celebrated his maiden Group 1 win aboard comeback galloper Explosive Jack, running down outsider True Marvel in the final bounds in a thrilling Sydney Cup finish. 

The gifted apprentice had been knocking on the door for a major and his moment came in one of the most difficult and testing arenas - a two-mile stamina test. 

Defending titleholder Knights Order ($16) led the field into the straight and kicked strongly before he was claimed by True Marvel ($151), who looked set to pull off huge Group 1 upset until Explosive Jack ($26) launched late to blouse them all. 

"When I saw (favourite) Cleveland not going that great I thought 'either I'm going really good or he's going really bad," Gibbons said. 

"Once I got him out the way I thought we were just going to whack away and run a gallant third or fourth but as they stopped, he didn't." 

Gibbons was born to be a jockey, following in the footsteps of his father, talented jockey Andrew. 

But while winning a major is a moment he has dreamed about, he says actually achieving it is surreal. 

"You can't explain it. I've always manifested these wins and thinking about what I'd do in the moment, but it just takes over for you," Gibbons said. 

"Just the pure joy of knowing that not only is it a great moment for me, but for everyone who's helped me get to this point. I'm sure they're enjoying it as much as me." 

The win was also special for trainers Ciaron Maher and David Eustace. 

An ATC Australian Derby winner at three, Explosive Jack suffered a suspensory injury after the 2021 Melbourne Cup that sidelined him for over a year and he came to the Sydney Cup (3200m) off a mixed campaign. 

Eustace praised his team's effort to manage the horse and get him back to his best 

"To get him back this horse, it's a really big achievement by everyone," Eustace said. 

"Mid-race I was kicking and screaming because they were going so slow and it just wasn't going to help any of our runners. 

"Without having dissected it, it was a pretty good performance for the horse to come from where he was and from a horse who hasn't showed a huge turn of foot his whole life really." 

The race was also a handy introduction to Gibbons with Eustace admitting he hadn't met the gifted apprentice before Saturday. 

"First time I've met him so it's not a bad meet and greet," he quipped. 

"He rode him great didn't he? He timed his run beautifully." 

It was a disappointing race for Joseph O'Brien pair Cleveland and Baron Samedi who finished third last and last respectively. 

Cleveland's jockey Kerrin Mcevoy said the horse travelled well in the run but couldn't quicken when asked. 

"He just never picked up at all," McEvoy told stewards.