"That period really helped me a lot", he said. "It's such an honour to play here", he added.
"This week has been one of the best I have had".
"David is such a tremendous guy, forget about his tennis". He played one very good match here, (and) one very bad match.
"It was an unbelievable effort". "So when my body's allowing me to do this kind of preparation, I feel I already have an advantage over any other player".
"I am lost for words".
The last player to win the trophy in their first year as a qualifier was Alex Corretja in 1998.
It wasn't the Roger Federer-Rafael Nadal matchup many fans had hoped for, but they were left satisfied as the two 26-year-olds delivered the longest final since the tournament returned to a three-set format in 2008.
Goffin missed Wimbledon after injuring his ankle at the French Open but is enjoying a dream end to 2017 with next week's Davis Cup final in France still to come.
"It was a special week for me", he said. It was a week with a lot of emotions, a lot of fatigue of course.
SC women's basketball champions decline White House invite
He began a series of stops on the South Lawn, then went to the State Floor and Rose Garden on the White House grounds. One team notably missing from the trip was the University of SC women's basketball team, the 2017 NCAA champions.
"I think now definitely we going to sit down with the team and reassess the whole year, see what we've done good, what we can improve".
Dimitrov had thrashed Goffin for the loss of just two games only four days earlier in the group stage but the crowd were treated to a classic this time around.
Goffin, who became just the sixth player in history to beat Roger Federer and Rafael Nadal in the same tournament, forced his opponent back in the opening game and broke in stunning fashion with a scintillating forehand victor.
He turned the set on its head in dramatic style by claiming six out of the next seven games to move ahead. In the second game of the first set Sock made two forehand errors and a double fault, Dimitrov was smart enough to play an aggressive tennis and break Sock at 30.
Goffin grabbed his chance in the next game with a forehand victor and confidently served out the set to force the game into a decider.
The errors continued to flow from a nervy-looking Goffin and Dimitrov finally secured the decisive break on his fifth set point when the Belgian thumped a forehand into the net.
However, the Bulgarian has had problems closing matches out this season - losing three times after holding match points - and had cause for concern when Goffin saved his first three to hold from 0-40 down at 2-5.
Sock, who saved four match points against Dimitrov in Indian Wells and one in Montreal two years ago, before going on to win on both occasions, saved three more, but at the fourth time of asking the Bulgarian wasn't to be denied.
Peers and Finn Henri Kontinen capped a memorable year with a dominant 6-4, 6-2 victory over top seeds Marcelo Melo and Lukasz.