Gosling was a Toon player prior to his move to the south coast and he played 90 minutes in the Cherries' 3-1 win.
The 26-year-old hailed the victory but is adamant that the team can't take their foot off the gas in the final stage of the season.
"It was a massive win for us," said Gosling.
"If we had lost then that could have dragged us back down, but three points move us further away and we're all delighted.
"To go to a stadium like that and play the football that we did is fantastic, we were fantastic for 90 minutes.
"It's a great feeling looking at the table but there are still a lot of games to come. That has to be our focus, we can't let up now."
Gosling returned to the starting line-up as Harry Arter missed out through injury, playing as a pair with Andrew Surman.
The Cherries have regularly played with five in midfield but Gosling believes they have proved on Saturday that they can play more than one way in Barclays Premier League.
"We do our homework," he continued.
"People know that a crowd can get on top of a team and it happens at most grounds. With 50,000 at St. James' it's louder and the way we press and the way we close the ball down went in our favour.
"It's slightly different with two in midfield, we have two up front and one drops so we can play both ways. Its good to be in a two, I think it shows we can play more than one way and I'm pleased to be back."