The Argentine was Boro's match-winner against the second-placed Bluebirds on Saturday netting a first-half penalty, his first league goal for the Teesiders team since September, 2007, to secure the impressive 1-0 victory.
However the pre-season promotion favourites remain 21st in the Championship just above the relegation zone on goal difference.
Arca told the Northern Echo: "It was an important win. It was a great three points and we have to take it into the Doncaster game next Friday and get something there.
"Hopefully we can turn things around. We showed against Cardiff that the quality is there. The work-rate and fitness are there, we just need to be consistent.
"We've played really well in some games. We've been up and down but we need to have a good run now. Christmas is coming up and there are a lot of games, and we need to take as much as we can from them."
Source: PA
Source: PA