Pompey booked their spot in the second round of the Emirates FA Cup with relative ease after seeing off plucky Harrow Borough at Fratton Park.
Marcus Harness scored the only goal of the game in the first half following good work from Mahlon Romeo.
And there were plenty of other chances to make the margin of victory greater, but the Blues were unable to convert them.
Danny Cowley made two changes from the side that drew with Cheltenham in the league earlier in the week.
Miguel Azeez was handed just his second start for the club, while Shaun Williams also returned, as Reeco Hackett and Louis Thompson dropped to the bench.
With sides allowed to name nine players on the bench, academy duo Harry Jewitt-White and Harvey Hughes were included named among the substitutes.
Ahead of Armistice Day, there was a minute’s silence before kick-off in memory of all those who made the ultimate sacrifice in service of their country.
When the action began, it did not come as a surprise to see the home side dominating both possession and territory.
Pompey were immediately on the attack, with Azeez and Ronan Curtis both seeing efforts blocked in quick succession.
Harness then sent in a teasing low delivery from the right that was agonisingly out of reach for both Azeez and John Marquis.
And a stretching Curtis was then unable to guide a header on target after meeting another fine cross from the lively Harness.
There was not too much happening at the other end, although Gavin Bazunu was called into action to deal with an angled James Ewington attempt.
Pompey were doing most of the attacking and Joe Morrell released Romeo down the right, with the full-back’s fierce drive parried away by Joe Strizovic.
Curtis was next to try his luck, collecting a pass from Connor Ogilvie and fizzing a long-range shot narrowly over the bar.
But the breakthrough did arrive on 28 minutes, when Romeo was afforded space to gallop down the right.
He then cut the ball back perfectly for HARNESS, who was left in plenty of space to coolly slot into the net.
The lead should have been doubled just a few seconds later, as a sliding Marquis somehow failed to connect with a low Harness centre.
And when Sean Raggett met an Azeez corner with a firm header, Strizovic dived to his left to push the ball to safety.
There was one heart-in-mouth moment at the opposite end, as Raggett’s short back-pass gifted a chance to Ewington, but Bazunu came to the rescue by tackling the striker.
The centre-back tried to make amends just before the break, with his header from a Harness corner looping onto the roof of the net.
Half Time: Pompey 1 Harrow Borough 0
Pompey picked up where they left off once the action restarted and Harness drilled a shot against the base of the post, with the loose ball not running for Curtis.
The opportunities kept coming and Romeo tried a drive after Marquis’ effort had been blocked into his path.
It was a clean strike from the full-back and Strizovic almost spilled it over the line, but recovered to grab hold of the ball at the second attempt.
But Harrow were still sitting deep, forcing the Blues to pass the ball around patiently and search for openings.
Cowley freshened up his forward line on the hour mark, with Azeez making way for Gassan Ahadme in the number 10 role.
And Thompson then replaced Williams, as the visitors continued to frustrate the Blues in their hunt for another goal.
They were looking to sit deep and soak up the pressure before trying to catch out their hosts on the break.
When Harness did get a shot away on 78 minutes, he was unable to catch out Strizovic at the keeper’s near post.
Cowley’s final intervention was a double switch, with Harness and Marquis withdrawn for Hackett and Michael Jacobs.
Harrow were trying their best to conjure some late cup magic, but a clean strike from George Moore flew straight into Bazunu’s arms.
But they were unable to test the keeper again during four minutes of stoppage-time, as the Blues ensured they would be in the hat for Monday night’s draw.
Pompey (4-2-3-1): Bazunu; Romeo, Raggett, Ogilvie, Brown (c); Morrell, Williams (Thompson 73); Harness (Hackett 83), Azeez (Gassan 60), Curtis; Marquis (Jacobs 83)
Goals: Harness 28
Subs not used: Bass, Freeman, Hughes, Jewitt-White, Hirst
Harrow Borough (4-1-4-1): Strizovic; Adenola, Mansfield, Preddie (c) (Cole 71), Taylor; Donnellan; Bryan (Otudeko 74), Keita (Wynter 79), Uche, Moore; Ewington
Booked: Adenola, Uche
Subs not used: Pearce, Biler, Tricker, Cain, Ozobia, Owoeye
Referee: Scott Tallis
Attendance: 6,869 (499 away fans)