(Reuters) - Chun In-gee welcomes the pressure of making her first defense of an LPGA major at this week's U.S. Women's Open, and the South Korean believes she is on the brink of more grand achievements.

The sixth-ranked Chun, who birdied three of her last four holes to register a one-stroke win last year at Lancaster Country Club, begins defense of her crown on Thursday at CordeValle in San Martin, California.

"Looking at my past career, I've played very well under pressure. So I'm going to enjoy this pressure," Chun, an eight-time winner on the Korean LPGA Tour and twice winner on Japan's tour, told reporters on Tuesday.

Chun has five top three finishes this year on the LPGA Tour, including a runner-up showing at the ANA Inspiration, the year's first major, but is still seeking her first win of 2016.

"The win at the U.S. Women's Open last year was my dream come true," said Chun. "If I continue to be like this, since this is a very long season, I'll come up with something really great. ... I'm looking forward to it."

Chun, who is also battling to qualify for Korea's Olympic team, had to overcome a bizarre injury earlier this season.

She hurt muscles surrounding her tail bone and had to miss March's HSBC Women's Champions event - won by compatriot Jang Ha-na - when a suitcase carried by Jang's father came crashing down an escalator and hit her at a Singapore airport.

"I'm fine. I would say about 99 percent perfect. When it gets cold, I get stiff, but it's not a problem at all," said Chun.

With so many Korean women crowding the top of the rankings list, Chun is not yet assured of an Olympic berth but she is not letting the Zika threat or security concerns distract her from he goal competing in the Rio Summer Games.

"I'm aware that there are a lot of concerns regarding health issues and security issues, but to be able to play at the Olympics is the biggest achievement and honor," she said about her quest.

Cheering her on at CordeValle are sure to be members of her Flying Dumbo fan club, who follow her to tournaments.

As an extra incentive, the legion of fans donate a dollar for every birdie she makes and she matches the amount for charity at the end of the season.

"So each and every time I face a birdie opportunity, it is a very precious opportunity for me," said Chun, nicknamed "Dumbo" for an insatiable curiosity that leaves her ears wide open to information and ideas.

(Writing by Larry Fine in New York; Editing by Frank Pingue)