Battling Rovers had to settle for a point in an entertaining match at Fratton Park, with only a great late save from home keeper Craig MacGillivray denying Alfie May a late winner.
Mallik Wilks' first-half strike had put Rovers into the lead, but the home side drew level through Omar Bogle in the second period.
Rovers pushed for the winner, with the home keeper in inspired form to tip efforts from John Marquis and May behind.
Aaron Lewis was handed his Rovers debut, with Matty Blair, Tyler Smith and Willks also coming into the starting line-up.
Wills was Rovers' main attacking outlet in the opening stages, with home right-back Nathan Thompson earning the first booking of the match after seven minutes for his second foul on the No.7.
The home side's first opportunities came after 12 minutes, with Herbie Kane blocking a Matt Clarke effort and Ben Close firing wide after a corner kick was cleared into his path.
Omar Bogle had two opportunities for Pompey after 20 minutes, with him heading wide from anion Donohue corner then directing a header straight into the arms of Marko Marosi after getting on the end of a deep cross from Tom Naylor.
Rovers went ahead on the half-hour mark when Wilks got on the end of a long ball down the middle of the pitch. He used his strength to hold off his man before a calm finish past Craig MacGillivray for his 10th strike of the season.
Donohoue fired over on the stroke of half-time, but Rovers went in with their lead intact.
There were no changes from the visitors at the break, but the home side brought on James Vaughan.
Bogle grabbed an equaliser for the home with 54 minutes on the clock, finishing a move from the left.
The goal gave the home side a confidence boost, with Vaughan trying an acrobatic overhead kick which went well over.
Grant McCann made his first changes with half an hour of the game to go, as May and Ali Crawford came on for Smith and Whiteman.
May saw an effort go just over with 20 minutes to go, while only a great last-ditch tackle by Thompson denying Blair.
Rovers pushed for the winner, with only a great fingertip save from MacGillivray denying Marquis after his fizzing low shot and a Kane effort deflecting into the hands of the home keeper when it could have gone anywhere.
Maoris was tested, too, having to come out quickly to stop Ronan Curtis after he was played through then pulling off a fantastic fingertip save from Close's long-range shot.
May went close to snatching the points when he won the ball on the edge of the area and let fly with an effort which was tipped brilliantly behind by MacGillivray.