Haslam had won the early race on Sunday and for most of the opening stages of this one it looked as if he may do the double.
However, Brookes and James Ellison ensured that he didn't have it all his own way and battled to make the race as tight as possible.
As the race progressed, Brookes had the lead but Haslam pulled away from Ellison and started to chase down the leader.
Haslam eventually took the lead again and, despite fierce pressure from Brookes, he got his second win.
There was worse news for Ellison who dropped down and conceded third, eventually finishing outside of the top five.
As with the first race the real story ended up becoming the battle for third, with Luke Mossey dropping out of the race and Glenn Irwin battling with Christian Iddon, with the former coming from a long way back.
Irwin did extremely well in the end to steal in right at the death and take third.
Read the original article on Eurosport: Haslam edges Brookes to take double at Donington