Nishikori used his speed Sunday in winning his third career title and second since October, beating Lopez of Spain 6-2, 6-3 in the U.S. National Indoor Championships at The Racquet Club.
"I knew he was a great player obviously, but he played in a way that I could not play my game I think," Lopez said. "He was very, very fast so I didn't find the way to be aggressive and to attack basically, which is the way I have to play, and I couldn't do it at all because he was always there. He knew where I was going to be, and he was there waiting sometimes."
Nishikori needed only 67 minutes to improve to 3-2 in finals. He won his first career title in Delray Beach in 2008, but now he quickly followed up becoming the first Japanese winner at the Tokyo Open in October by starting 11-2 this year with another title.
He said he wasn't really thinking about anything during the match when asked about reading Lopez's moves so well on the court.
"Guess I was reading his serve," Nishikori said. "Yeah, he was hitting good serves and good percentage, but I was hitting really good and everything goes well."
Seeded fifth, Nishikori was the only seed to reach the weekend. He finished the tournament without dropping a set in taking the $291,800 winner's check, and he is expected to move from No. 22 in the ATP rankings to about No. 16.
"It is such a big step for me to win these tournaments, and yeah 500 (points), that's big for me now," Nishikori said about the ranking points this win brings. "Try to be top 10, that's my goal this year. It is important to win big points like this, and I think it's a good start ... I have a lot of things to do of course but yeah, it's a good start."
Bob and Mike Bryan, the top seeds, won their 85th career doubles title earlier Sunday, beating James Blake and Jack Sock 6-1, 6-2.
Lopez, who beat Nishikori in April 2011 in Barcelona on clay, was looking for his own third career ATP title and first since Johannesburg in February 2010. At 31, Lopez was playing in his eighth career final with a chance to become the oldest player on tour this season to win. A victory would have moved him into the top 30 in rankings from No. 47 at the start of this week.
The Spaniard led the tournament with 38 aces, including eight in the final. But he also had three double-faults and managed to win only 16 percent (3of 19) of points on his second serve.
Nishikori broke Lopez twice in the Spaniard's first three service games to go up 4-1 in the first set.
"It's the perfect start for him," Lopez said. "It was perfect moment. One-love, break, and then he starts playing better and better. It's not about one game ... It would have been difficult to win today I think."
Nishikori also broke him again to start the second, even though Lopez pushed the game to deuce and even had the advantage. Lopez couldn't close it out, and Nishikori got the advantage back with a forehand down the line and then a backhand passing shot.
Lopez tried to rally in the second game in his best chance to break Nishikori, jumping out to a 40-0 lead off the Japanese's serve. Then Lopez hit a couple forehands long, and he lost a challenge that a Nishikori shot had been long only to have replay show it touched the back edge of the line for deuce. Nishikori won the next two points to go up 2-0.
Nishikori said he told himself to cut out the unforced errors.
"I broke him first, seems easy for me. But if he got the game, anything happen and yeah I knew that was important game for me," Nishikori said. "I made my serve and tried to play ... tried not to do unforced errors."
Then Nishikori finished off the match efficiently serving out before breaking Lopez one last time for the title. Lopez came to the net, and Nishikori answered with a backhand passing shot to reach 15-40. Lopez had a cross court winner, then hit a backhand that went wide.
Nishikori saw the ball going wide, dropped the racket and raised his arms in celebration.