Pompey’s biggest away following of the season will travel to Oxford on Saturday.
Presently 2,035 tickets have been sold for the Kassam Stadium clash with the promotion-chasing U’s.
The ticket allocation is 2,300, with the Blues expected to sell out in advance for the fixture.
That away attendance already comfortably eclipses the previous best of 1,405 who were present for the October league match at Plymouth.
That 1-1 draw was televised and kicked off at 12.15pm but, impressively, still attracted Pompey’s highest away following up to this point.
For Blues fans, it will be a second trip to Oxford this season having ventured there in the Johnstone’s Paint Trophy, also in October.
There were 1,132 visiting supporters out of a crowd of 3,697 for the occasion which saw second-half goals from Patrick Agyemang and John Marquis claim a 2-1 victory and send Guy Whittingham’s side through.
This latest encounter will represent the 12th time Pompey have broken through the 1,000-mark for an away fixture this season as they continue to lead attendance figures in League Two.
There were 998 present at the New Year’s Day fixture at Southend, while the full allocation of 802 was taken up at closest-rivals – in distance terms – AFC Wimbledon.
Tickets are priced at £19 for adults, £15.50 for students with an NUS card, £11.50 for seniors (65 plus) and juniors (under 16) and free for children under seven.
However, supporters are reminded tickets will not be sold on the day of the game.
Meanwhile, there is still room on the club’s official coach travel.
Priced at £18 for adults and £15 for juniors, it can be bought by calling 0845 389 0644 or visiting Lucketts Travel in Fareham.