Terry hails Costa contribution at Everton
The Spain international opened the scoring after just 35 seconds at Goodison Park and added his second late on in one of the most remarkable games in the Premier League's recent history.
And Terry singled out the former Atletico Madrid man's talents as he took his tally for the season to four, with Chelsea continuing their 100 per cent start to the campaign.
"He's been brilliant," Terry told Sky Sports. "I played against him in the Champions League and realised he was a top player, but when you see him every day you realise he's literally got everything.
"He's got off to a flying start and long may it continue, because that was the difference today."
Jose Mourinho's side sit top of the table after three wins from three games and Terry is already eyeing the club's first Premier League title since 2009-10.
"I think the belief has been there from day one," he added. "Didier [Drogba] spoke before the game and said, 'It's been too long since we won the league', that's obviously our aim.
"We've started very well. It was important today as well as the boys go away on international break. It's a couple of weeks now until our next game so it's vital we got the win."