Substitute Johnny Ertl rescued a point for Pompey as they earned a 1-1 draw with Wycombe Wanderers.
The high-flying visitors edged the battle in the first 45 minutes and took the lead early in the second half when Pompey failed to clear their lines and Sam Wood poked home from close range.
But the Blues produced a decent response, with Joe Devera and Craig Westcarr both spurning glorious opportunities to draw level.
Instead, it was Ertl – on as a half-time substitute for Jack Whatmough – who finally restored parity in the 70th minute as he swivelled on Dan Butler’s corner and rifled home a cracking volley.
Both sides then had late opportunities to snatch all three points as the clock ticked down but it remained honours even.