Morecambe substitute Jack Redshaw earned his side a 2-2 draw with a late goal to deny Portsmouth a much needed win.
The home side trailed 2-1 when Redshaw's right foot shot from 12 yards somehow squeezed under visiting goalkeeper Trevor Carson who had been Pompey's hero earlier in the game with a first-half penalty save from Padraig Amond.
The afternoon started well for Portsmouth after Jake Jervis gave them the lead in the 10th minute. Jed Wallace was the provider with a dangerous low cross from the left and Jervis reacted sharply to get ahead of Morecambe defender Mark Hughes to turn the ball past Barry Roche from six yards.
Morecambe hit back with Andy Fleming firing a shot into the sidenetting moments later and levelled in the 21st minute when skipper Hughes met a cross from home debutant Jamie Devitt to head into the top left-hand corner of Trevor Carson's goal.
The goal sparked a period of dominance from the home side who missed the chance to go ahead six minutes before the break when Amond won a penalty after being brought down in the box. The striker picked himself up to take the spot kick but was denied by an excellent save from Carson.
Amond was made to pay for his miss when Pompey broke free and scored a second two minutes before the break. Wallace was again the inspiration as he created space for Marcos Painter to cross into the danger area for Jervis to score again from close range before the game's late twist.