"It was my best performance of the tournament," Djokovic said after the 86 minute match against the sixth seed. "It came at the right time against a great player."
By taking home the 1.028 million dollar top prize, Djokovic surpassed Roger Federer as the all-time ATP earnings leader, his $98,199,548 nudging him beyond the $97,855,881 amassed by the Swiss 17-time grand slam champion, who pulled out of Miami with a stomach virus.
Before the win at Miami, Djokovic shared the record with Rafael Nadal for most wins at Masters events – considered just below the grand slams in terms of prestige. Djokovic added: "The fact that I have now managed to win the most Masters ever is a remarkable achievement I'm very proud of.
"To put myself in position to have the records and be in the history books is a great accomplishment. But I didn't think much about it before the match. It didn't serve as a distraction. Hopefully I can make many more records."
Djokovic, who also claimed his 63rd career ATP title, will head to the European clay court season in good heart as he girds his loins in the quest to win the French Open - the only grand slam to have eluded his talented grasp.
"Miami has been a springboard for everything that has come after," Djokovic said. "Opened a lot of doors for me. Made me realise that I could beat the best players in the world."
Nishikori made 30 unforced errors as he lost to Djokovic for the seventh time in nine meetings. "It was a tough match," said the Japanese 26-year-old. "Playing Novak is always a great challenge for me.
"My serve wasn't going well. It was a shame to have that because he has such a great return and I felt a lot of pressure on my service games.
"In the second set I tried to change. I tried to be more aggressive, but I was missing a lot with my forehand. There were too many unforced errors to beat him."