Neil Robertson slammed Ronnie O'Sullivan’s use of Triangle Chalk after the 50‑year‑old lost a 13‑12 last‑round encounter to John Higgins. The chalk, still unique on tour, reportedly caused troublesome kicks and table marks that disrupted play.

Higgins, who had trailed 8‑3 and 9‑4 before snatching victory, noted the chalk’s impact when a kick sent a red off‑target. Robertson, who beat Chris Wakelin 13‑7, said the chalk “makes an absolute mess of the table” and should be banned.

WST allows any chalk, but clubs increasingly refuse the old formula. Robertson pledged to refuse practice partners the chalk and called the incident “chalkgate.”

With Higgins advancing to his 20th quarter‑final, the debate over chalk standards highlights how equipment choices can influence outcomes at the world level.