Match ends, Portsmouth 1, Stevenage 1.
Stevenage substitute Brett Williams scored a stoppage-time leveller to keep Portsmouth off the top of League Two.
Teenager Conor Chaplin deservedly broke the deadlock for Pompey, ghosting past Fraser Franks before beating goalkeeper Jesse Joronen at his near post.
But the visitors battled hard and got their reward when Williams glanced home a header from Charlie Lee's long throw in the dying seconds.
Portsmouth dominated and will rue two missed chances from Gary Roberts.
Pompey would have gone top on goals scored had they won, after Plymouth Argyle lost 1-0 at Oxford United.
Portsmouth manager Paul Cook told BBC Radio Solent:
"We've played 14 games, lost one, just keep going. Unfortunately today we couldn't hold the lead.
"We're just huffing and puffing, we just don't look at it. It's a lot more effort, rather than quality.
"We'll just go back to the training ground, look at the DVDs like you do, and just keep working hard."
- 15BartonSubstituted forAtanganaat 78'minutes
- 5BocoSubstituted forChaplinat 70'minutes
- 9TubbsSubstituted forLaveryat 61'minutes
- 33KennedySubstituted forLeeat 72'minutes
- 15TongeBooked at 69mins
- 18ParrettSubstituted forWilliamsat 90+2'minutes
- 20AkinyemiSubstituted forConlonat 57'minutes
- Andy Woolmer
- Shots on Target
Second Half ends, Portsmouth 1, Stevenage 1.
Corner, Portsmouth. Conceded by Armand Gnanduillet.
Attempt blocked. Conor Chaplin (Portsmouth) right footed shot from outside the box is blocked.
Goal! Portsmouth 1, Stevenage 1. Brett Williams (Stevenage) header from the centre of the box to the top left corner. Assisted by Charlie Lee.
Foul by Gary Roberts (Portsmouth).
Tom Conlon (Stevenage) wins a free kick in the defensive half.
Hand ball by Tom Pett (Stevenage).
Substitution, Stevenage. Brett Williams replaces Dean Parrett.
Michael Doyle (Portsmouth) wins a free kick in the attacking half.
Foul by Dean Parrett (Stevenage).
Attempt missed. Conor Chaplin (Portsmouth) left footed shot from the right side of the box is close, but misses to the left.
Attempt missed. Tom Pett (Stevenage) right footed shot from the centre of the box is high and wide to the right.
Foul by Nigel Atangana (Portsmouth).
Mark Hughes (Stevenage) wins a free kick in the attacking half.
Delay in match Dean Parrett (Stevenage) because of an injury.
Substitution, Portsmouth. Nigel Atangana replaces Adam Barton.
Goal! Portsmouth 1, Stevenage 0. Conor Chaplin (Portsmouth) left footed shot from the centre of the box to the bottom right corner. Assisted by Enda Stevens.
Substitution, Stevenage. Charlie Lee replaces Ben Kennedy.
Substitution, Portsmouth. Conor Chaplin replaces Romuald Boco.