It was a singles debut on Centre Court for both women but the gulf was all too clear as Barty wrapped up a 6-1 6-1 victory in just 53 minutes to reach the fourth round for the first time with a 15th consecutive win.
The considerable consolation for Dart is that by reaching the last 32 she had far exceeded expectations and her ranking will rise from its current 182 into the top 140.
"I'm super happy with my performances this week," said Dart. "I think today is such a good learning curve for me. She played great. She didn't let me in the match at all.
"It's obviously a tough lesson to learn. It's been a great tournament for me. I should take a lot of positives from it. This is all so new to me. I'm just trying to take everything in my stride and build on it for the next tournaments."
As is customary on middle Saturday, the start of play was delayed while the sporting royalty in the Royal Box was introduced and the work of the members of the Armed Forces who serve as stewards applauded.
The Red Arrows' fly past came a little late and, unfortunately for Dart, in between her first and second serves.
This was the second time this year that the 22-year-old has found herself on one of the biggest stages in tennis taking on a star of the game after losing 6-0 6-0 to Maria Sharapova in the first round of the Australian Open.
She would have been desperate to avoid the same fate and she held game points in her first two service games but was unable to take them and found herself 5-0 down inside 20 minutes.
There was a loud cheer when she got on the board in her third service game, stepping up her aggression, but three aces from Barty saw her sweep to the opening set.
The 23-year-old was ranked 17th this time last year but has taken the change in profile and pressure completely in her stride.
Barty has not so much as dropped a set since the semi-finals of the French Open, winning the Nature Valley Classic title in Birmingham with five straight-sets victories, and she was simply far too good for Dart.
The British player's weak serve was taking a pounding, while she was having little success on Barty's. Dart did make it to 0-40 at 1-4 only for Barty to reel off three excellent points, and it was all over soon after.
Dart was in floods of tears after the Sharapova loss, but said: "I think today I handled my emotions a lot better. It was really nice to have the British fans out there, which I think helped me a lot.
"Not many people can say you played the third round of Wimbledon against the world number one on Centre Court. It was pretty special to be out there. I definitely enjoyed every minute."
Barty added: "I think today I was able to overpower Harriet. A lot of games could have gone either way, especially early on. Harriet will have a fantastic career and I'm sure Centre will be her favourite court."
The top seed will take on American Alison Riske in the fourth round on Monday.