A Golden Set - I hadn't heard of it until it happened - is when one player scores all 24 points in a set. It happened once in men's tennis, and once in women's.
The women player is actually listed below, but you won't figure it out if you didn't know. Yaroslava Shvedova at Wimbledon 2012, third round, beat no other than Sara Errani 6-0, 6-2, scoring the first 24 points in a row (not sure when Sara had her first point in the second set, so it may be more - wait I have the match - one sec - Errani DID score the first point of the second set...).
(The first time was when American Bill Scanlon beat Brazilian Marcos Hocevar in the first round of the WCT Gold Coast Classic at Delray Beach, Florida, on February 22, 1983. Scanlon won the match 6-2, 6-0.)
And I distinctly remember Venus having a 3-unforced error match a few years ago...
NOTE: unforced errors and 24 points in a row aren't the same. Federer would have had to win all his opponents points as well, to get the Golden set.
So here are more matches, the first, with Nadal, in English, the rest Spanish! Go figure....