Stuart Broad and Jofra Archer cranked up the intensity in the nets as they looked to prove their fitness for the Boxing Day Test against South Africa.
The pace duo have been laid low by illness throughout the warm-up period, missing all five days of match practice.
They have been gradually building the workloads back up over the past 48 hours, though, and both bowled five overs at full pace in a training session at SuperSport Park in Centurion.
The pair also batted, before walking laps of the ground to acclimatise to rising temperatures.
They were joined at the session by Jack Leach, who has suffered the same flu-like symptoms over the last week and is also yet to bowl a competitive delivery on tour.
Leach is less likely to play, even if he is passed fully fit, with England understood to be favouring a pace-heavy attack supplemented by the occasional spin of Joe Root and Joe Denly.
Craig Overton and Dom Bess, who were late call-ups as cover for the trio, took part but are unlikely to come into consideration for selection.