For one-quarter of her life, Stacy Lewis was in a back brace due to scoliosis. So having to overcome a 2-stroke penalty on her caddie was easy.

Lewis, 28, had rods and screws surgically implanted in her back while she was in high school to her correct her scoliosis. She sat out her freshman year at the University of Arkansas as a result.

Once she got on the course, Lewis dominated to the tune of 12 victories in 47 tournaments in her collegiate career.

Having overcome scoliosis, Lewis became a dominant collegian. According to her coach, she also overcame being one of the shyest players on the team.

Now in her fifth full year on the LPGA Tour, Lewis has climbed to the top of the Rolex World Rankings.

Her final step was made a little more difficult because of a step her caddie, Travis Wilson, made in the third round.

Lewis hit her drive into a fairway bunker on No. 16. While discussing what type of shot to hit, Wilson walked into the bunker to aid his judgement. When he was in the bunker, Wilson spun his foot in the sand.

Rules officials determined that he was testing the surface of the bunker, and therefore Lewis was given a 2-stroke penalty. Instead of entering the final round two shots off the lead, Lewis went to the final round four behind.

Lewis joked after the third round, "Thank you to the viewer that called in because he gave me some more motivation."

Just what third-round leader Ai Miyazato and the rest of the field needed -- a more determined and motivated Lewis.

Miyazato may have stumbled to a double-bogey on the 16th hole in the final round, but it was Lewis that grabbed the title. She ran off four birdies in a 5-hole span to fly into the lead. An easy par at the last gave her the RR Donnelley LPGA Founders Cup title, and the No. 1 spot in the Rolex World Rankings.

"That was my goal kind of since the middle of last year and I really didn't think it would be possible this quick," admitted Lewis on Sunday. "We've only played four tournaments this year and it's just crazy. We still have so many more events this year. We have majors coming up, Solheim, and so much more to play for and I'm just excited about the rest of the year more than anything. I'm having a blast on the golf course, and to be No. 1 in the world, it's what everybody out here on tour is working for,"

They may have only played four events, but Lewis tops the money list by more than two times the amount that No. 2 Inbee Park has earned.

There is an easy explanation as to why. Lewis has won the last two events, and finished third and 15th in the other two. She has broken par in 13 of her 16 rounds this year and has shot in the 60s in 11 of her 16 rounds.

Lewis said she didn't think it was possible to ascend to No. 1 that quickly, yet three of the others six players that reached No. 1 actually were less accomplished when they reached the top of the rankings.

This victory was the seventh on the LPGA Tour for Lewis. Jiyai Shin, Yani Tseng and Ai Miyazato all reached the top spot in the rankings with fewer wins.

Shin and Miyazato reach No. 1 in 2010. At the time, they had six and four victories, respectively. Tseng had five wins when she became No. 1. Three of those five were major championships though.

Lewis' ascension to the top spot in the rankings means she is just the seventh women to reach No. 1 since the rankings started in 2006, and she is just the second American woman to do so.

In comparison, the men's world rankings have seen 16 players reach No. 1 since the rankings were established in 1986. Tiger Woods, the third of four Americans to reach No. 1, was atop the rankings for 623 weeks from 1998 to 2009.