He was finally able to make his debut in the 1970–71 Australian season in the First Test of the 1970–71 Ashes series at Brisbane. He did not however make a large impact, scoring 0 and 2 and taking 2/95, resulting in his immediate dismissal from the team. He was recalled for the Seventh, and final Test of the series at the spin-friendly Sydney Cricket Ground, where took 3/42 as England were dismissed on the first day for 184. In the Australian innings he ducked into a short ball from John Snow. This resulted in crowd trouble which forced English captain Ray Illingworth to evacuate his players from the ground. Jenner returned to bat at 235–8 and made a brave 30, last man out on 264 – giving Australia a lead of 80 runs – and took 1/39 in the second innings, but Australia lost the test and The Ashes.