Steve Cotterill praised the doggedness of his men to salvage a point at Boro.
Luke Varney rescued his team in stoppage time with a predatory finish to earn Pompey a 2-2 draw.
David Norris had cancelled out Marvin Emnes’ opener for Pompey, before Rhys Williams had put the home side ahead again.
Then Varney latched on to debut-making Christian Dailly’s blocked shot to grab a draw.
Cotterill lauded the spirit of his men to keep going until the death.
He said: ‘We showed great spirit. They’ve all done that since I’ve been at the club.
‘I knew it was a tough game and we knew we were up against it.
‘Whatever way you look at it, coming to Middlesbrough was tough.
‘We had a lot of knew faces, so we’re pleased with the result.
‘We only had two subs yesterday, but registered Ryan Williams and got Christian Dailly in.
‘So we’re happy all told with the start.’