Tiafoe arrived at the All England Club having captured his first grasscourt title at the Stuttgart Open last month but it was the experienced Dimitrov, a former semi-finalist here, who prevailed over two days.
The first things Tiafoe highlighted when asked to give his thoughts on Dimitrov prior to the match were the Bulgarian's first serve, his net game and his slice.
Tiafoe had clearly done his homework, having beaten Dimitrov four years ago at the Australian Open in a last-16 clash he described as "an absolute war", but this time the American had no answer for the variety of shots in his opponent's arsenal.
Dimitrov did not disappoint and was virtually unstoppable on serve, firing 13 aces and winning 92% of his first serve points to go two sets up and leave Tiafoe on the ropes before play was suspended on Saturday early in the third set.
When they resumed on Sunday, Dimitrov consolidated an early break and Tiafoe lost his cool in no time, taking his frustration out on a ball by launching it into orbit between points.
Dimitrov, on the other hand, was calm and collected as he went about his business with powerful shots from the baseline and flawless touches at the net to fire 33 winners, leaving the younger and faster Tiafoe with no answers.
The Bulgarian brought up three match points without breaking a sweat and sealed victory with a deft volley at the net after sending Tiafoe desperately scrambling for a return.