His goal was icing on the cake following strikes from Michael Owen and Obafemi Martins.
Guthrie: "I joined in with the boys on Saturday for my first session of the week, and I was feeling it a bit in the game towards the end.
Guthrie Happy To Notch Number One!
"And I just made a late run into the box. It was a good pull back by Shola. It was about using the pace on the ball, and getting the right connection.
"It flew in, and I really enjoyed it, especially as it was in front of our fans.
"Hopefully, I can start pushing on from this, and score goals more regularly. All the best midfielders in the world score goals, and that's the aim.
"The first half was a bit tight, and it was just a case of trying to quieten down the crowd.
"We came out in the second half, took our chances, and probably deserved the win.
"It was a case on building the two away games, when we kept two good clean sheets.
"Portsmouth will get goals with the players they've got, but we were solid at the back, and it was a good win. Once we got the goal, we just wanted to control the game."