It was a case of too little, too late for Pompey against Doncaster at the Keepmoat Stadium.
Trailing to strikes from Reece James and Fejiri Okenabirhie, they did not find the net themselves until deep into stoppage-time.
A neat John Marquis finish was almost followed by a leveller with the final kick of the contest, only for a last-gasp block to ensure the hosts held on.
And Kenny Jackett was disappointed that his side were unable to take anything back with them to the south coast.
The Blues boss said: “We started very brightly, won the ball back in a couple of good situations and almost scored before they went ahead.
“Then we perhaps could have won a penalty following a shoulder to shoulder on Haji Mnoga inside the box.
“That first goal would have lifted us, but there were too many one-v-ones where we looked vulnerable.
"It looked like we were going to get an equaliser right at the death and it was a great tackle on the line to deny us."
“We’ve conceded two goals down our right-hand side and although we got a decent foothold in the game after the break, Doncaster were leading and didn’t need to come out too far.
“We needed something to spark us during that period and unfortunately it didn’t come until the 94th minute.
“It looked like we were going to get an equaliser right at the death and it was a great tackle on the line to deny us.”
Pompey went top of the table just before Christmas, but have now dropped to fifth in the League One standings.
Jackett said: “We’re disappointed with how up and down we’ve been and have to keep working hard to earn confidence back.
“It’s something that’s easy to lose and hard to get, so we have to dig deep and make sure we stick together.
“Doncaster have closed the gap on us and we need to find some better form, but there are still 45 points to play for.”