The Columbian winger curled a stunning strike into the far top corner to give the Seagulls a 2-1 lead, before they ran out 3-1 victors against the Hammers to move up to 13th in the Premier League.
Izquierdo laughed afterwards at his team-mates suggestions it was a cross and not a shot and said: "My team mates think that I crossed, they don't believe in me. I swear not. I received the ball and the only thing was to shoot."
Izquierdo added it is the best goal he has scored and said: "Until now, yes. The first goal in the Premier League was against them and also was very nice but this goal in the moment I scored was special.
"I enjoyed it. It was a massive celebration, I let out the feelings in that moment.
"It was time to celebrate and enjoy."
Talking about his celebration, where he swirled his shirt above his head and was chased by his team-mates, Izquierdo said: "It was the emotion of the moment. It was very important for the team and for me.
"You couldn't imagine the emotional feelings I had in that moment, I only ran around like Forrest Gump.
"(laughing) I ran more in the celebration than in the game."
On the importance of the victory, Izquierdo said: "It's big. We were at home and it's important for us, for the supporters and for the table.
"We need the points and each game will be like a final."
Keep up with all the top football news and transfer gossip from England, Scotland and beyond with footballwire.co.uk