But great heroics late on from Andy Blignaut and Heath Streak were required to push Zimbabwe past 300 after only Andy Flower impressed from the top-order with 71.
Meanwhile, Zimbabwe's worst humanitarian and economic crisis since its independence from Great Britain in 1980 rages on, with a cholera epidemic that has claimed nearly 2, 000 lives since August.
McGrath is expected to pass other great fast bowlers, Richard Hadlee (431) and Kapil Dev (434) in Zimbabwe to become the fourth-highest Test wicket-taker of all time.