After losing the toss and being sent in to bat first, Free State batsmen had difficulties batting under overcast conditions with only two batters reaching the double figures.
Paterson who returned with career best figures of 7 for 20 in 9 overs was assisted by Francois Plaatjies who finished with 3/19 in 8 overs.
WP also started their innings on a back foot when they lost the first wicket of Matthew Kleinveldt (2) in the second over and another one of Alistair Gray (3) in the eleventh over.
In-form batter, Sharn Gomes who scored his third half century in just five innings this season and right-hander, Pieter Malan constructed a 57-run third wicket partnership to recover WP’s innings. Left-arm quickie, Abraham Pienaar gave Free State the breakthrough when he dismissed Malan for 14 runs and went on to dismiss Gomes (53) four balls later.
The 77-run fifth wicket partnership between Sybrand Engelbrecht (41 not out) and Bradley Barnes (29 not out) took WP past the 150 mark. At close of play they are 153/4 in 57 overs. They lead by 95 runs with six wickets remaining in the first innings.