Antonelli is now 45 points clear in the championship race.
The world number two admitted he was “stuck in neutral” for most of his four rounds at Royal Birkdale.
Argentina were denied a try that, if converted, would have snatched a draw deep into overtime.
Sobers made 93 Test appearances for the Windies across 20 years.
The JP McManus-owned winner continued the good run of Joseph O’Brien.