Ferrer started brightly and raced into a 4-1 lead in the first, but Dolgopolov fought back to force the tie-break and scraped the set 7-6.
In the second set Ferrer again squandered an early break and was pushed to another breaker by the Ukrainian, but this time he regrouped and won comfortably.
The third set was all Dolgopolov, as he broke twice to go 5-1 up and when forced to serve for it was more than equal to the task.
As one sided as the third set was, the fourth went comfortably Ferrer's way as he played some superb shots to win it 6-1.
Ferrer got the crucial break in the sixth game of the final set to move 4-2 up and managed to consolidate it, although he had to save a break point to do so.
It left Ferrer serving for the match, which he managed without much difficulty to move on to face Ivan Dodig in the fourth round.