Pompey have sold out their allocation of tickets for the League One game at Charlton.
The Blues travel to The Valley on December 9 (3pm kick-off).
And they'll be cheered on by their biggest away following of the season, with Pompey fans snapping up tickets for the game in quick-fire time.
Just under 3,000 were put on sale yesterday, including an extra 1,000 supplied by the hosts.
But just 24 hours later and the club have sold their entire allocation of tickets for the game, ensuring a packed Jimmy Seed Stand.
Pompey's away following for the clash promises to be a season's best to date.
The current record stands at 1,966 for the August trip to Wigan, with 1,810 making the journey to Oxford two weeks before that.
In contrast, only 206 Blues fans travelled to Charlton for last month's Checkatrade Trophy fixture against the Addicks - a game that attracted a crowd of 1,307.