Linebacker has delivered a stunning upset in the Randwick Guineas, defeating the star colt Broadsiding to secure his co-trainer Tom Charlton’s first Group 1 win.

Broadsiding, the $1.60 favourite trained by James Cummings, was expected to claim his fourth Group 1 win, but jockey Zac Lloyd executed a perfect plan, placing Linebacker ($9) in a position to make the favourite chase.

Tracking Tenbury Wells in front, Lloyd made his move early in the home straight, with Broadsiding emerging as a challenger. Linebacker responded strongly, holding off Broadsiding to win by a half-length, with Swiftfalcon finishing third, just a neck away.

Charlton, who joined the John O’Shea stable in 2019 and became co-trainer last year, was overwhelmed by his first Group 1 victory.

“I’m just so thankful to my boss and all the clients,” Charlton said.

Trainer John O’Shea celebrated his 30th Group 1 win, noting that the plan was to have Linebacker third-up for the Randwick Guineas after solid previous performances.

Jockey Zac Lloyd praised Linebacker’s toughness, saying, “He’s a superior miler,” while Broadsiding’s rider James McDonald acknowledged the winner’s strong performance.