All 30,945 tickets have been snapped up for the game which is being dubbed "The Battle of Britain", and it looks increasingly likely that Sunday's second semi-final at Huddersfield's McAlpine Stadium between Australia, the World Cup holders, and New Zealand will be a 19,000 sell-out.
"Obviously we are delighted, but we are not surprised," said Maurice Lindsay, the tournament director. "The whole competition has been magnificently supported. We expect to have 10,000 Welsh fans at Old Trafford, so there should be a tremendous atmosphere for what should be a terrific clash."
Two sell-outs over the weekend will take the aggregate attendance for the first 14 Centenary World Cup matches to more than 200,000, with a large attendance anticipated for the final at Wembley a week on Saturday.
The tournament has had a worldwide television audience of around 370 million, and attendances for the Emerging Nations competition have also been encouraging.
Although a crowd of more than 35,000 watched Saturday's Manchester football derby between United and City, Old Trafford's redevelopment plans have restricted the use of the North Stand for the semi-final.
However, those unable to get tickets will not miss out as both semi-finals are being televised live by the BBC.Reuse content