Brett Pitman’s second-half double and Jamal Lowe’s 18th-minute opener moved the Blues within two points of second-placed Barnsley having played a game fewer.
The Adams Park clash proved to be a thriller, with the Chairboys also scrapping for their lives at the opposite end of the table.
Here’s what those closest to the action had to say about the game...
Pompey manager Kenny Jackett
It was always going to be a different type of test, but it was one we rose to very well. I did think in terms of the decisions we didn’t get the rub of the green.
It's easy for me to say that after we got the win. It's not something I would have been sighting after the game if we’d lost the game.
We looked quite a classy team at times. In both halves it was quite difficult to stop their flow coming into our box.
Wycombe boss Gareth Ainsworth
It should’ve been a penalty, right at the end. It’s hard to take. We deserved something from the game. Their second goal was a gift from us, the third a great free-kick, but we still did enough to get something.
Blues striker Oli Hawkins
We always knew it was going to be tough coming here, the record of the top six clubs in the league showed no-one had won here previously.
A lot of their pressure was putting the ball into the box, Craig (MacGillivray) made some great saves and we held on and got the three points.
Chief sports writer Neil Allen
Pompey were comfortable at times, yet made to cling on for victory.
Nonetheless, a fourth-straight League One win maintains their magnificent late promotion charge.
Brett Pitman was a class act with two superb goals, but Craig MacGillivray's goalkeeping heroics were just as crucial, with at least four excellent stops.
Not entirely convincing in the end for the Blues, yet they ground out three crucial points.
Pompey reporter Lewis Mason
Pompey held their nerve to secure what was another crucial win at Wycombe.
The Blues twice held a two-goal advantage but substitute Scott Kashket's stunning late strike left Kenny Jackett's men facing a tense final ten minutes.
But Pompey showed great grit to grind out another key three points.
That made it four successive league wins as they sit two points off an automatic promotion place in fourth.
Although the Blues may have to settle for a play-off spot, they are at least keeping the pressure on Barnsley and Sunderland should either slip-up in the final run-in.