Brett Pitman scored a brace on his debut to ensure Pompey began life in League One with victory over Rochdale.
The striker bagged an impressive individual goal after Keith Keane had been dismissed for the visitors at Fratton Park.
But there was a nervous edge to the closing stages, with substitute Jamal Lowe also sent off for the Blues.
That changed to elation in stoppage-time, however, as Pitman headed home to complete a memorable afternoon for the skipper.
Kenny Jackett handed starts to three summer signings in his first competitive match as Pompey manager.
Luke McGee, Tareiq Holmes-Dennis and Pitman all featured, while there was also a surprise appearance for Drew Talbot at right-back.
There were a mixture of emotions before kick-off, with Michael Eisner and other members of the Tornante Company applauded onto the pitch.
It was a more sombre occasion after that, however, with a minute’s applause to remember former Blues players Fred Evans, Pat Neil and Jimmy White, who all passed away over the summer.
Supporters were also paying their respects to fan Alan Dobson, who sadly died during the recent friendly against Bournemouth.
Once the action got underway at a sunny Fratton Park, it was the visitors who looked the more threatening.
Andy Cannon blasted a shot over the crossbar, although there were not too many opportunities to test McGee.
And Rochdale’s threat was blunted somewhat when they were reduced to 10 men on 21 minutes.
Conor Chaplin collected a loose ball and charged towards goal, only to be crudely upended by Keane just outside the box.
Referee Lee Probert immediately brandished a red card and the centre-back was forced to trudge off to the dressing room.
Pompey were unable to make the free-kick count, though, as Carl Baker’s delivery evaded everyone and went behind.
Calvin Andrew then did well to nip in ahead of Christian Burgess and head behind Baker’s dangerous corner.
The hosts went close again from the resulting flag-kick, as Pitman found space to nod narrowly past the post.
But the Blues were dealt a blow of their own late in the first half, with Holmes-Dennis going down injured on the left.
He limped off to be replaced by Lowe, with Gareth Evans dropping to right-back and Talbot moving across to the left.
The first half had been rather slow to get going, but the second exploded into life after just 34 seconds.
It was a fine effort from PITMAN, who picked the ball up on the left and – through a mixture of skill and persistence – found space to slot it into the net.
There was soon an opening for the visitors at the other end of the pitch, although Ollie Rathbone dragged his effort wide.
Rochdale then won a free-kick 25 yards out, but Reece Brown could not quite force his shot through the defensive wall.
An error from Josh Lillis almost handed Pompey a second goal on 69 minutes, with the keeper tearing off his line to try to beat Chaplin to the ball.
But he only succeeded in chesting it into the path of Lowe, whose cheeky lob landed narrowly wide of the post.
Jackett made his second substitution moments later, with Chaplin making way for Kal Naismith in the Blues attack.
And Lowe made way on 81 minutes – although there was nobody to replace him after the substitute was shown a red card.
He stretched to win the ball, but caught Jamie Allen and Probert decided it was enough to warrant a sending off.
That ensured a more fraught end to proceedings than perhaps was necessary, but Pitman eased those nerves in stoppage-time.
Evans got free down the right and picked out the unmarked striker in the box, with PITMAN expertly guiding his header past Lillis and into the net.
Pompey (4-2-3-1): McGee; Talbot, Burgess, Whatmough, Holmes-Dennis (Lowe 39); Baker, Rose; Evans, Pitman (c), Bennett; Chaplin (Naismith 71)
Goals: Pitman 46, 90+2
Sent off: Lowe
Subs not used: Bass, Davies, May, Main, Kabamba
Rochdale (4-4-2): Lillis; Brown, Keane, McNulty, Ntlhe; Cannon (Davies 75), Camps (Rafferty 59), Allen, Rathbone; Henderson (c), Andrew (Done 59)
Sent off: Keane
Subs not used: Collis, Canavan, Inman, Williams
Referee: Lee Probert
Attendance: 18,009 (471 away fans)