A sign of Djokovic’s greatness has been his ability to dominate much younger opponents on the biggest stages over recent years.
With Djokovic’s technique, mentality and athleticism showing few signs of weakening, Shelton was the latest young pretender to be taught a lesson.
The second seed enforced his quality and experience from the start, serving smartly and returning Shelton’s biggest weapon well before intensifying the pressure.
Djokovic remained utterly calm and controlled to quieten the home crowd, further flattening the mood at the start of the third set.
Shelton made a trip to the locker room in a bid to change the dynamic, but two double faults led to Djokovic breaking in the first game with a superb passing winner.
Winning in straight sets looked a formality for the 23-time major champion until Shelton found his best level of the match to break back for 4-4.
The world number 47 created a set point at 5-4 which Djokovic saved with a pinpoint service winner, before a sloppy game allowed Djokovic to strike for 6-5.
Shelton was not finished yet. He saw Djokovic push a forehand wide on match point and broke back to force a tie-break, only for Djokovic to ramp up the intensity again before taking his second match point.