Republic of Ireland international Long scored the final goal in the Baggies' 3-0 win at Southampton on Saturday.
Marc-Antoine Fortune opened the scoring after six minutes, with Romelu Lukaku and Long adding to the tally in the second half against a Saints side that had been unbeaten in their previous six matches.
Victory at St Mary's saw Steve Clarke's side set a new club record for Premier League matches won (14) and points gained (48) and Long is hopeful West Brom, currently eighth in the table, can finish the season in ninth or above to secure their best ever finish in the Premier League era.
"I felt like we have been playing well over the last couple of weeks," he said.
"Maybe we were a little slow out of the blocks and we got caught because of that before. I think the only really bad performance was the first half last week against Newcastle (the game finished 1-1).
"We held our own up until that and things just didn't go our way. We started off very well and put ourselves in a great position to have a great season.
"I think the players and manager have deserved it so hopefully we can kick on for the last four games and get right up there."