In 1968-69 he took 30 wickets (25.26) against the visiting West Indies and at 27 became the youngest man to take 200 Test wickets, a record since beaten. Another 21 wickets (21.00) came on the Indian tour of 1968-69, but when the Australian team proceeded to South Africa his form slumped (1/333 in four Tests) and they were whitewashed. It led to suspicions that he had contracted hepatitis. He played in the first four Tests of the 1970-71 Ashes series against England, taking 4/66 in the Second Test at Perth, the first played at the WACA Ground and 2-22 in the first ever One Day International at Melbourne. In the Fourth Test at Sydney McKenzie retired hurt after being hit in the face by a bouncer from John Snow as the England fast bowler took 7-40 in England's 299 run victory. He recovered sufficiently to break Geoff Boycott's forearm in a tour match just before the vital Seventh Test, but was not recalled and was left stranded on 246 Test wickets, two short of Richie Benaud's Australian record. He was only 29 years old.