The 27-year-old South African, who has represented Eastern Province and KwaZulu Natal Inland in first-class cricket back home, took all 10 wickets for Tickhill as they defeated Barnsley by 124 runs in the Yorkshire Southern Premier League.
It is the first time a 10-for has been achieved in the Yorkshire League since it was split into north and south divisions in 2016.
Six of his victims were bowled, three caught and one lbw, and Koekemoer’s figures were 14.4-5-38-10.
Barnsley won the toss at Shaw Lane and elected to field, the visitors making 189-8, with opener Ross Diver prominent with 53 and former Nelson Mandela University student Koekemoer scoring 40 at number four.
Beck Frostick returned figures of 2-29, backed up by Waqas Tanveer (2-40) and Oliver Jackson (3-45), but they were nothing compared to what happened after tea.
Only opener Oliver Bennett (18) and William Nicholson (5) lasted more than 30 balls as Koekemoer ripped through Barnsley’s innings, with Adi Sreedharan (10-5-7-0) providing miserly support for the overseas all-rounder as the hosts were toppled for 65 in 28.4 overs.
Fourth-placed Tickhill welcome reigning Premier Division champions and early leaders Appleby Frodingham to Alderson Drive on Saturday.
Doncaster Town’s comprehensive eight wicket win over Elsecar at Town Fields also produced another devastating spell of bowling.
The visitors were 58-2 when James Keast took five wickets in 27 balls at the cost of just two runs. Umar Amin also claimed 3-13.
Elsecar crashed to 68 all out and Town knocked off the runs with relative ease to record back-to-back wins and move up to seventh in the table.
Town go to Whiston Parish Church on Saturday and visit Derbyshire side Ockbrook & Borrowash in the ECB National Club Championship on Sunday.
Conisbrough claimed their first win of the season in the Championship with a 40-run victory over Barnsley but Sprotbrough slipped to a six-wicket defeat against Hallam. Askern Welfare went top of Division One in the Pontefract League by beating Hooton Pagnell.