Thankfully, Hope Akpan's subsequent awful miss deep into stoppage-time ensured there was no late drama to deny the Blues.
The Bradford City midfielder was presented with just Craig MacGillivray to beat from the inside the box as the hosts chased a leveller.
Inexplicably, he lifted his shot over the onrushing keeper and also the crossbar as the gaping goal remained unscathed.
Evans, who handed the Blues a first-half lead, had departed the pitch by that stage, replaced by Ben Close in the 76th minute.
And rather than watch from the bench in horror as Akpan's glorious opportunity unfolded, he shut his eyes and hoped for the best.
Pompey's skipper said: '˜Bradford had one or two chances at the end, while Craig made a decent save in the first half, but I don't think they troubled us too much, whichÂ is testament to the whole team doing well.
'˜At the end, I'm not sure what he (Akpan) was doing to be honest.
'˜He dinked it over the bar and that was probably their chance, when it didn't go in you fancied us to hold on.
'˜I must admit, I shut my eyes when it came to him, everyone later said it went over the bar. I was desperate to be the matchwinner!
'˜He broke through and you just thought 'That's going to be a goal', but luckily he missed.
'˜I'm not really good with stuff like that, I'm just glad that we won.
'˜It is a big win, we knew it was going to be tough going there, it's a good club, it's a big club and I think their league position is possibly a little bit false.'
Pompey increased their lead to three points at the head of League One following Saturday's win.
The 1-0 Valley Parade victory also represented a seventh away triumph in the league and eighth overall this term.
Yet Evans insists the squad remains grounded '“ and capable of more improvement.
He added: '˜There's a certain amount of confidence that we possibly didn't have last season, which comes downÂ to winning games and getting points on the board.
'˜I don't think anyone is getting carried away, it's only November and the lads are just enjoying winning games and getting results.
'˜The performances have been good, there's probably still room for improvement, but that's the same for everyone.'