Jaaskelainen was thrilled to see the Hammers making the most of their opportunities.
He told whufc.com: "They were three great finishes. You can see West Brom are a good team, but we gave a very good performance.
"The manager said in the week that we need to be more ruthless in front of goal and we did that on Saturday.
"It's good when you go 2-0 up because it becomes easier to control the game. Maybe we dropped a little too deep at the start of the second half, but we created chances when we counter attacked and got the third goal.
"It was a great three points on Saturday and we can go on from here now. We've got eight games to go and we want to finish as high as possible."