Less than 24 hours before the start of Wimbledon, the third-seeded Dutchman scored a 6-4, 7-6 victory in 68 minutes over French qualifier Guillaume Raoux 6-4, 7-6, the second time he has won this tournament in seven appearances.
Krajicek broke Raoux once in the first set but neither player managed a service break in the second, forcing a tie-break which the Dutchman won 9-7.
Krajicek hit 14 aces in the final and did not lose a single service game throughout the tournament. He will now move from sixth to the fifth in the new ATP world rankings today.
Krajicek starts the defence of his Wimbledon title against little-known German Marcello Craca in the opening match on centre court today.
The first match on the new No 1 Court pits Britain's Tim Henman, the 14th seed, against Canadian Daniel Nestor.
Henman, a quarter-finalist last year, will be cheered on by 11,000 fans on Wimbledon's showpiece show court, which will be officially opened today. Henman and Nestor will be followed by German Michael Stich, the 1991 champion, and the American former world No 1 Jim Courier.
Stich, making his final Wimbledon appearance before he retires at end of the year, can expect a strong challenge from Courier, always a tough competitor.
Both French Open champions will be in action on the first day with the Croat Iva Majoli, the fourth seed, playing Argentina's Mariana Diaz Oliva on Court Two and Brazilian Gustavo Kuerten facing American Justin Gimelstob on Court Three.
Kuerten, seeded 11th thanks to his sensational Paris win, promised to change his flashy, yellow and blue outfit for more traditional clothes.
One of the most exciting matches of the first day should be the one between seventh seeded Australian Mark Philippoussis and Britain's Greg Rusedski, two of the hardest hitters on the men's circuit. They will play on Centre Court immediately after Krajicek and Craca.
Other matches to watch include second-seeded American Monica Seles, chasing the only Grand Slam title to elude her, against Australian Rachel McQuillan on No 1 Court and the hard-hitting Croat Goran Ivanisevic against the Romanian Dinu Pescariu on Court Two.
The American teenager Venus Williams, seen by many as a likely candidate for the No 1 position in the near future, makes her Wimbledon debut against Poland's Magdalena Grzybowska on Court Three.