Yet Goffin, beaten in all six prior meetings with Federer, turned the tables to win 2-6 6-3 6-4 and become only the sixth player to beat Nadal and Federer in the same tournament.
"I proved to myself that I'm in the right place, and I deserve to be here in this tournament".
The semifinal line-up: Dimitrov vs Sock; Federer vs Goffin.
And the set duly stayed on serve until the eighth game, when an unfortunate net cord for Sock was followed by two double faults in quick succession that offered Dimitrov two chances to break. I just want to keep the momentum going.More news: I 'Should Have Left' UCLA Players In Jail Over Father's Comments
But as Dimitrov savoured that one of many firsts by looking forward to a break from the game, Goffin will be in action again next week for Belgium in the Davis Cup final against France. He played one very good match here, (and) one very bad match.
A bruising first set went in Sock's favour before Zverev took the second easily.
Dimitrov's confidence carried into the second set, where he brought up the first break point in the sixth game, only for Goffin to produce a stunning cross-court backhand victor to save it.More news: LeT Commander among six militants killed in Bandipora, IAF commando martyred
Only the US Open offered more than $3m to its victor this year. 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.
The season-ending extravaganza ATP Finals at London's O2 ends another memorable year which will be covered via our website www.skysports.com/tennis with live blogs and updates as the season reaches its climax. "Then the semi-final, to beat Roger for the first time here in such a big event, big tournament, it was the flawless moment", Goffin, who beat a hobbling Nadal on Monday, said.
"I was a little bit exhausted in the third", Goffin said. "I had to play a few matches obviously back-to-back against solid opponents". At 3-0 in the second set, Goffin was digging his heels into the game.More news: The NFL is not backing down from Jerry Jones' threats
Since teaming up with Dani Vallverdu late in 2016, Dimitrov has won four titles, including his first Masters trophy in Cincinnati, and recaptured the form that propelled him into the top 10 for the first time in 2014.