Yuvraj fell to the fourth ball after lunch when he was stumped attempting to drivespinner Ollie Rayner, who then struck again when Mahendra Dhoni was trapped in front trying to work the ball to leg.
But Natal-born Amla, whose grandparents migrated from India, overcame the tricky spell and reached his double hundred with a delightful drive off spinner Virender Sehwag.