Amla had made five when he missed an intended pull off the fast bowler, the ball crashing into the grille of his helmet after he was beaten for sheer speed. He had several minutes of on-field treatment before walking off.
The Proteas were then 14 without loss in the fourth over chasing 312 to win on an Oval ground where Amla made a South Africa record 311 not out in a Test against England in 2012.