Rafael Nadal insists he will never lose his appetite for success as the world No 1 gets stuck into his bid for the eighth Grand Slam title of his remarkable career.

Nadal moved into the second round at Wimbledon on Tuesday with a typically belligerent 6-2, 6-4, 6-4 win over Japan's Kei Nishikori that underlined his determination to regain the All England Club crown he was forced to surrender last year.

The Spaniard missed out on the chance to defend the title he won in 2008 due to tendinitis in both knees but he is back to his best now after winning the French Open for a fifth time recently.

That Parisian triumph took Nadal's tally of Grand Slams to seven and American legend John McEnroe believes Nadal could win another six or seven Grand Slams before he retires.

The 23-year-old agrees that he still has plenty of time to put more titles in his trophy cabinet back home in Mallorca because he will never lose his desire to compete at the highest level.

"Thank you to John for saying that. I have seven Grand Slams and I will see when I finish my career. I am very happy to have seven. That's more than what I dreamed a few years ago," Nadal said.

"If I am still playing well, if I am still improving my tennis, I hope I have more chances to win.

"But the important thing always is the same - to have enough motivation to keep improving and practice every day at 100 percent.

"That's what I did all my life. I hope to keep doing it for a long time. I want to have a lot of chances for more titles because it is very difficult to win every Grand Slam."

Nadal's hopes of adding Grand Slam title No 8 on men's singles final day here at Wimbledon would be boosted significantly if Roger Federer continues his recent struggles.

Federer needed a dramatic fightback to defeat unheralded Colombian Alejandro Falla in the first round here on Monday after the defending champion fell two sets behind.

The world No 2 has failed to win any of his tournaments since lifting the Australian Open title in January but Nadal believes his win over Falla will be a major boost to his morale.

"For sure, it is going to be a very important win for his confidence," Nadal said.

"The first round is always very difficult but normally for him it is easier than for the rest of us because he plays so well on grass.

"Falla is a great player and he had his chance but he wasn't able to play his best tennis in the moment that he needed to."

Federer's early exit from the French Open against Robin Soderling last month ended his incredible run of 23 successive Grand Slam semifinal appearances.

Nadal would love to get somewhere near Federer's current record of 16 Grand Slam titles but he believes the level of consistency needed to make so many semifinals will never be matched.

"Every one of his records is amazing but to reach 23 semifinals in a row at Grand Slams is the most impressive," Nadal said.