The Reds were staring down the barrel of a third consecutive league defeat when Gareth Evans fired Pompey ahead two minutes before the interval.Â
But Cauley Woodrow, passed fit following a calf problem, came to the rescue by netting the equaliser in the 61st minute.Â
The former Fulham striker guided Brad Potts' exquisite cross from the right-hand side into the bottom corner.Â
However, the Tykes could have taken all three points had they brought their shooting boots.Â
Dani Pinillos fired wide, Kieffer Moore volleyed over and Craig MacGillivray produced a fine performance in goal, leaving Stendel frustrated.Â
"The performance was very good; our plan against Portsmouth was good as we outplayed them at the most of times," the German said.Â
"Only the result was not what we wanted, I think we more than deserved to win this game. It's the only point I'm not satisfied with.
"We wanted to shoot a lot of times in this game. It was a target for us to shoot more, but too often it was too close to the goalkeeper.Â
"His performance was good but I think the shots were not far enough in the corner and sometimes too easy to save for him."
The draw left Barnsley without a win in four league matches, meaning they slipped two points outside the top six with a game in hand.
But with fixtures against Blackpool, Peterborough, Charlton and Luton to come over the festive period - teams that sit in the top eight - Stendel knows things can change quickly.Â
'We have 25 games and it's not the best. We are not in the top six in the table, but we cannot change," Stendel said.
"All we can do is play with the same passion like today and I think for sure after the next game we'Ä¼l get in the top six.
'For me it's not much different, playing the side that's top of league or Wycombe. We want to win every game and every time we don't win, I'm disappointed.'