Frank Lampard's free-kick was bundled in deep into stoppage time to earn Chelsea a 1-0 triumph at Stamford Bridge.
Terry told BT Sport 1: "Recently dropping points away to West Brom, it's important to pick up three points at home.
"We're top of the league and sitting well. It's down to the others now to catch us."
There was some confusion as to whom Chelsea's match-winning goal should be attributed to. Lampard's set-piece eventually pinged in off goalkeeper Tim Howard, but Terry insisted he definitely got a touch on the ball.
"Great ball from Lamps, (I) just managed to get a touch on it and I think it came off Howard in the end as well but I'm delighted with the win and the three points," Terry said.
"They made it quite difficult but they're a very good side and playing well under (Roberto) Martinez and it was a tough game today."