Pompey secured a second pre-season friendly win in succession, but were made to work hard for their 2-1 victory at Westleigh Park.
Gareth Evans fired them ahead from the penalty spot just before half-time, only for former Blues triallist Roarie Deacon to draw the Hawks level.
It was Brett Pitman who came off the bench to grab a late winner, however, in front of a huge crowd of 3,500 sun-worshipping supporters.
There were three changes from the side that began the midweek rout of UCD in Dublin.
Ross McCrorie and James Bolton both missed out with knocks, while Jamal Lowe was also absent, as Ben Close, Anton Walkes and Evans all came in.
Anybody expecting another goal-fest was in for a disappointment, with chances at a premium during the opening stages on a warm afternoon.
A dangerous Walkes delivery was turned behind before it could reach Ronan Curtis at the back post, while an Evans free-kicvk cleared the crossbar.
The hosts were certainly not looking over-awed and an effort from Josh Taylor was deflected wide of Craig MacGillivray’s post.
Pompey’s keeper also made a regulation save to deny Andy Drury, as the game continued to drift along without much excitment.
The visitors created a fine chance on 28 minutes, however, and Ross Worner made an excellent stop to keep out Louis Dennis’ header from point-blank range.
Ellis Harrison then beat the Hawks number one to the ball, but the angle was tight for the summer signing and his cut-back was dealt with.
The striker was involved again just before the break and when he was brought down in the box by Dean Beckwith, referee Matt Russell pointed to the spot.
It was the skipper who stepped up to take the spot-kick, with EVANS slamming his effort straight down the middle to open the scoring.
There was still time for another opening before the interval, with Worner again doing well to keep out a fierce strike from Curtis.
Havant & Waterlooville 0
The second half got off to a livelier start, with Worner immediately having to get down to keep out Lee Brown’s free-kick.
A volleyed effort from Jonah Ayunga was then brilliantly dealt with by MacGillivray, as the Hawks tried to find a leveller.
But the action soon switched ends once more and Curtis almost caught Worner out at his near post after neatly stepping inside.
It was the home fans who were celebrating on 56 minutes, though, when substitute Chris Paul teed-up Deacon for a neat finish into the bottom corner.
The usual curse of the pre-season friendly soon followed, with a wave of substitutions for both sides stemming the flow of the contest.
Another brief interruption was caused by a fan who ran on to the pitch to request a selfie with Christian Burgess, who obliged, and MacGillivray, who sternly ordered him off the pitch.
It was two of Pompey’s newcomers who combined for their winner on 80 minutes, with Brandon Haunstrup doing well down the left and providing the assist for PITMAN to slot home.
Hawks (4-1-2-1-2): Worner (Latham 58); Read (Tarbuck 58), Beckwith (Cook 60), Magri, Straker; Bailey (Paul 46); Taylor (Dennett 65), Fogden (c); Drury (Walton 46); Deacon (Ridge 83), Ayunga
Goals: Deacon 56
Pompey (4-2-3-1): MacGillivray; Walkes (Burgess 73), Downing, Raggett, Brown (Haunstrup 70); Naylor (Morris 70), Close; Evans (c) (Hancott 84), Dennis (Cannon 70), Curtis (Pitman 70); Harrison
Goals: Evans 44 (pen), Pitman 80
Subs not used: Bass, Mnoga, Dandy, Bridgman, Teggart, Stanley
Referee: Matt Russell
Pompey kicked-off their pre-season schedule with an emphatic 11-0 victory at UCD.
Brett Pitman hit a hat-trick, while there were braces from Louis Dennis and Ronan Curtis, with Jamal Lowe, Gareth Evans, Joe Hancott and Ben Close also scoring against the top-flight Irish club.
Following almost two weeks of training at bases in Portsmouth and Dublin, the Blues returned to match action with less than a month until the start of the new League One campaign.
Pompey – with summer recruits James Bolton, Paul Downing, Sean Raggett, Ross McCrorie and Ellis Harrison all starting – looked bright from the off and opened their account after just 10 minutes.
Dennis looked electric in the opening half and he crossed from the right, with CURTIS doing just enough to force his header home.
And the lead was soon doubled following more good work from Dennis, who delivered from the opposite flank, leaving LOWE with plenty of time to slot past Conor Kearns.
The visitors almost added a third just seconds later, but Lowe’s effort was saved and the ball ricocheted against the bar.
That would be Kearns’ final contribution, with the keeper taken off injured and replaced between the sticks by Tom Murphy.
The lead was increased midway through the half, however, as DENNIS latched on to Lee Brown’s quickly taken free-kick and bent a shot around the new stopper.
CURTIS then got his second of the evening on 39 minutes when Harrison’s cross evaded its intended target of Dennis.
Instead it fell for the Republic of Ireland international, who chested the ball down and emphatically found the net.
There was an almost instant fifth goal, as DENNIS rounded off an impressive first half display by receiving Harrison’s pass, spinning past the last defender and coolly finishing.
Jackett changed his entire team at the break, but that did not stop the goals from flowing in the second half.
EVANS became the fourth different scorer of the contest, with a blocked pass bouncing back to him and a powerful shot striking the underside of the crossbar before finding the net.
PITMAN then got his first on the hour mark, capitalising on some slack defending to take a touch and find the target from close range.
He might have earlier scored in more acrobatic fashion, but a scorpion-style attempt narrowly cleared the bar.
Murphy was being continually called into action, getting down low to save first from Anton Walkes and then deny Evans at the near post.
But an eighth goal did arrive, with PITMAN picking the defence’s pocket following an Evans cross to double his personal tally.
Teenage full-back HANCOTT – playing a more advanced role – was next to score, being quickest to react when Pitman was denied by Murphy.
The travelling Blues fans wanted 10 and skipper PITMAN duly obliged by completing a 20-minute treble.
Aaron McGrath took too much time over clearing the ball, allowing the striker to steal possession and bend it around Murphy.
The scoring was finally complete six minutes from the end, with UCD unable to clear under pressure and CLOSE emphatically finishing.
Pompey’s run of friendlies continues at Westleigh Park on Saturday when they take on neighbours Havant & Waterlooville (3pm kick-off).
UCD: Kearns; Tobin, Farrell, McEvoy, McClelland; Doyle (c), Keaney; O’Farrell, Kinsella-Bishop; Dignam; Mahdy
Subs: Murphy, Griffin, Mullen, Akinsete, Daly, Ring, Ryan, Boore, Keane, Smith, McGrath
Pompey: MacGillivray (Bass 46); Bolton (Walkes 46), Downing (Burgess 46), Raggett (Casey 46), Brown (Haunstrup 46); Naylor (c) (Morris 46), McCrorie (Close 46); Lowe (Evans 46), Dennis (Cannon 46), Curtis (Hancott 46); Harrison (Pitman 46)
Goals: Curtis 10, 39, Lowe 16, Dennis 24, 41, Evans 49, Pitman 60, 76, 80, Hancott 78, Close 84
Referee: David Dunne