Pompey suffered more late heartache as Ollie Watkins snatched a 90th-minute leveller for Exeter at St James Park.
Conor Chaplin’s neat first half finish looked to have ensured that the visitors would be taking all three points home from Devon.
Jayden Stockley had been the biggest threat for the Grecians, but missed a hat-trick of chances to punish his former side.
Instead it was Watkins who found the target just before the end to break the hearts of the travelling support.
Paul Cook stuck with the same side that beat Cambridge at Fratton Park at the weekend.
His Exeter counterpart Paul Tisdale – presented with an award before kick-off in recognition of passing 500 games in charge of the club – restored former Blues loanees Lee Holmes and Stockley to the starting line-up.
The game was just 22 seconds old when Chaplin missed a great opportunity to break the deadlock by mis-controlling Kal Naismith’s cross.
Christian Burgess was also off target with a header in the opening stages, while the ferocity of Holmes’ pass back to Bobby Olejnik almost caught the goalkeeper out.
There were not an abundance of clear-cut openings, but it was still Pompey looking the more likely to score as the first half progressed.
Doyle drew a smart stop from Olejnik with a 30-yard volley on 25 minutes after a corner had only been cleared as far as the visiting skipper.
But Stockley then should have punished his former side, only to guide Christian Ribeiro’s cross straight into the arms of Ryan Fulton.
And he was made to pay for his profligacy moments later, as Pompey went up the other end of the pitch to take the lead.
It was a fine effort from CHAPLIN, who neatly chested the ball down on the edge of the box before steering it into the bottom corner.
He might have had a second soon after, bursting inside to collect Marc McNulty’s cut-back, but failing to make a clean connection.
Exeter did enjoy a spell of pressure late in the half and Stockley again wasted a good opportunity by glancing another Ribeiro cross wide.
Watkins then cut inside and unleashed a curling drive that Fulton did well to parry clear before the ball was hacked to safety.
Exeter City 0
The second half was slow to spark into life, although a corner for the hosts did lead to a melee in the Blues box.
Pompey were not offering too much at the other end either and Naismith’s long-range effort flew over after the winger had wriggled past a couple of challenges.
They almost doubled their lead in comical fashion on the hour mark, however, thanks to some wonderful improvisation by Chaplin.
The teenager was left on the floor after colliding with Olejnik in a race for the ball, but still managed to scramble a shot inches past the post.
That seemed to shake the Grecians into action and a Stockley header had to be cleared behind by Burgess.
The resulting corner then made its way to the striker’s feet inside the box, but his flicked effort just about went wide.
And that proved to be Stockley’s last chance to make an impact as he was withdrawn with Troy Brown in a double switch for Exeter on 65 minutes.
Pompey were next to go close after Naismith was barged over by Watkins right on the edge of the area.
Chaplin stepped up to take the free-kick, but although his effort curled over the wall, it also cleared the crossbar.
Cook looked to shore things up on 79 minutes, with goalscorer Chaplin making way for Gareth Evans.
And more valuable seconds were used up a few moments later as Adam Barton was introduced for Kyle Bennett.
There was a scary moment when the ball found its way to Alex Nicholls in the box late on, only for the midfielder to blaze his shot high over the bar.
But it looked like the Blues had done enough to hold off the Grecians until Watkins shimmied into space and angled home into the net.
Exeter might even have snatched a winner deep into stoppage-time, but Nicholls’ free-kick was turned around the post by Fulton.
Exeter (4-3-2-1): Olejnik; Ribeiro (Morrison 79), Brown (Grant 65), Moore-Taylor (c), Woodman; Nicholls, Oakley, Watkins; Wheeler, Holmes; Stockley (Noble 65)
Goals: Watkins 90
Subs not used: Pym, Tillson, McAllister, Taylor
Pompey (4-2-3-1): Fulton; Davies, Burgess, Webster, Stevens; Hollands, Doyle (c); Naismith, Chaplin (Evans 79), Bennett (Barton 82); McNulty
Goals: Chaplin 31
Subs not used: Bass, Freeman, Clarke, Haunstrup, Tollitt
Referee: Brendan Malone
Attendance: 3,855 (695 Pompey fans)