However, four more titles this year - taking his career total to 17 - saw him finish in the top five, with Federer dropping out of the four-man monopoly at the top of the rankings.
"For this year, my goal was trying to play in the same level [as] the top guys," the 2009 US Open winner told reporters. "I am the only player who beat all of them in this season, which means something for me.
"I think I did a great season. Maybe I [will] finish in the top 5 after three and a half years. [It] is really good [to] see my ranking and my name in the top positions."
"They don't beat me easy, and I beat [them in] some tournaments. All the matches are close, but in the end they still beat me because they have a little difference. I will be working hard on that."
Federer will Nadal in the first ATP semi-final, while Djokovic takes on Stanislas Wawrinka in the second.