The Spanish striker scored a hat-trick in Chelsea's 4-2 demolition of Swansea City.
For those who haven't read my blog before, I have a bet on Costa to be the top scorer in the Premier League this year and earn a free £2 bet every time he scores a goal.
With yesterday's goals added to his tally, the player remains on top of the scorer list with seven goals.
7 goals x £2 = £14.00.
A nice return on a £20 investment.
And we're only four weeks into the season.
Now all I have to do is pick a few winners with my free bets.