Pompey got the festive season well underway following an exciting duel with Sunderland at Fratton Park.
Both team showed plenty of energy throughout the game, but it was the second half when the match really took off.
Evans opened the scoring for Pompey from the penalty spot after Glenn Loovens had been sent off for a foul on Oli Hawkins.
Ronan Curtis soon doubled the advantage, with Sunderland’s Luke O’Nien reducing the deficit in front of the biggest crowd Fratton Park had seen for over seven years.
Late worries were squashed when the ever energetic Ben Thompson added another for the Blues, who continued to attack right up until the final whistle.
Speaking about the match, Blues Manager Kenny Jackett said: “It was a really good performance, particularly in the second half. We upped the tempo and got the goals that secured the win.
“Before the break it was quite cagey and there weren’t too many chances, although there was a big save from our keeper.
“But, overall, I felt it was two very good teams going at each other and we didn’t want to leave anything out on the pitch.
“I don’t think the referee had any other choice for the penalty and Gareth took it fantastically to give us the lead.
“We went further ahead and then their lad got the other side of Ronan, who was otherwise excellent, to score.
“But we had many chances throughout the half and could have got even more, so the result was thoroughly deserved.
“We’ve got 50 points before Christmas which is a fantastic achievement by the players and shows great consistency.
“We didn’t seem to have any injuries and hopefully everyone’s good, so now we’re looking forward to Boxing Day.”