Potchefstroom - Craig Alexander ended with a career-best 6/38 as the Dolphins wrapped up their first four-day victory of the season by thumping the Highveld Lions by 398 runs early on the final day here on Sunday.
Alexander trapped Dieter Klein leg before wicket with the ninth ball of the day without adding to his overnight 17. He then accounting for Junior Dala (5) and Eddie Leie (4), both caught by David Miller.
Harmer then stepped up to mop up the tail with the off-break bowler taking out Shaun von Berg (15), Rowan Richards (18) and Ethy Mbhalati (13). Van der Merwe remaining unbeaten on 61 as the game ended shortly before lunch.