Pakistan level ODI series in S.Africa

Pakistan have levelled their one-day international series with South Africa after winning the fourth match by eight-wickets.

Pakistan bowler Usman Shinwari has ripped through South Africa's tail end in their fourth ODI. (AAP)

Usman Shinwari has taken four wickets before Imam Ul-Haq struck 77 to lead Pakistan to a thumping eight-wicket win over South Africa in the fourth one-day international in Johannesburg.

Pakistan's victory levelled the series at 2-2 on Sunday and set up a decider in Cape Town on Wednesday.

The series has been overshadowed by the four-match ban handed to Pakistan captain Sarfraz Ahmed after he admitted breaching the International Cricket Council's anti-racism code in comments he made to South Africa's Andile Phehlukwayo during the second ODI.

Sarfraz has now returned to Pakistan, but his team did not miss him on the pitch as they dismissed their hosts for just 164 in 41 overs.

Shunwari took 4-35 as he ripped through the tail, with opener Hashim Amla top-scoring for South Africa with 59.

The tourists sealed victory inside 32 overs, Imam's 91-ball innings and useful contributions from Fakhar Zaman (44) and Babar Azam (41) helping them to 2-168.