He spoke afterwards about his newly-found form and applauded his team mates for their unwavering support.
"It's not just from the boss but my team mates too; they've never abandoned me and have always given me support. Now things are working out well for me," said Costa.
"You have a tough time; every striker needs goals. I think now I am more involved in the team's moves - I always knew that the goals would come.
"Of my team mates I've got no complaints at all; I have to thank them because they have always supported me and never let me just give up. It's normal to get criticism because the people always ask for more from the national team players."