Norwich and Pompey had to settle for a point apiece after a cracking game.
Leon McKenzie and David Bentley both went close early on, but Yakubu put Pompey ahead after Robert Green spilled Nigel Quashie's shot.
Norwich dominated after the break and Darren Huckerby netted the rebound after Shaka Hislop saved his penalty.
Patrik Berger's stunning free-kick made it 2-1 but Simon Charlton headed a second Canaries equaliser before Gary Holt smashed a shot against the bar.
Both sides made a bright start, and Berger smashed in a shot from 25 yards which went just over before McKenzie sent a header from Bentley's superb cross narrowly wide.
Pompey almost went behind in embarrassing circumstances when Berger ducked under Bentley's corner and the ball hit the post with Hislop looking unimpressed.
Diomansy Kamara had a superb opportunity to finish off a flowing counter-attack and even though Yakubu delayed his pass, he should have done better than blasting over.
He had a better chance after Berger played him in with a neat return pass but fired well off target.
It was becoming something of a one-man show for the Senegal striker and he showed tremendous power and pace to race through the home rearguard, but again the finish was lacking.
Bentley fired over from his 30-yard free-kick as Norwich tried to raise some cheer for the home fans, but they were silenced soon after.
Quashie unleashed a swerving long-range effort which Green could not handle and Yakubu, who has struggled this season, took his time before firing in.
Hislop was then hurt in a collision with McKenzie at the other end and Bentley tested him with a 25-yard curler, which bounced just in front of the Pompey keeper.
It could have been 2-0 just after the break when Berger stole the ball off Charlton and played it through to Yakubu, who was set to score before Marc Edworthy made a fine covering tackle.
Bentley deserved something for his running and guile and he almost fashioned something when his half-volley went straight at Hislop.
Huckerby had been quiet but he was starting to look more dangerous and his cross just eluded McKenzie.
But an equaliser was not long in coming and Huckerby netted after he had been brought down by Taylor and then seen his penalty palmed out by Hislop.
Norwich's joy was shortlived, however, as Charlton brought down Quashie and Berger cracked in a wonderful free-kick from 25 yards out.
A remarkable spell of play ended with Charlton making amends by heading in Drury's cross after defensive uncertainty from Portsmouth.
Holt nearly fired Norwich ahead with two powerful shots from outside the box, the first of which crashed off the bar.
The pace had to slow down but there was still time for Yakubu to force a save from Green and Paul McVeigh to send a drive the wrong side of the post.
Norwich: Green, Edworthy, Charlton, Fleming, Drury,
Jonson (McVeigh 72), Holt, Francis, Bentley, Huckerby,
McKenzie (Svensson 79).
Subs Not Used: Ward, Doherty, Helveg.
Goals: Huckerby 63, Charlton 67.
Portsmouth: Hislop, Griffin, Primus, Unsworth, Taylor,
Cisse (LuaLua 69), Faye (Hughes 78), Quashie, Berger,
Kamara (Fuller 60), Yakubu.
Subs Not Used: Ashdown, Mezague.
Booked: Griffin, Taylor, Faye.
Goals: Yakubu 37, Berger 65.
Ref: M Messias (S Yorkshire).