Stacy Lewis continues her pursuit of the world No. 1 ranking this week at the NW Arkansas Championship, teeing it up against a strong field that includes two-time defending champ Yani Tseng. \"I\'m ready to take her on,\" Lewis said. \"I want to be No. 1 in the world. I know I\'m two, but I\'m not happy with that.\" The 27-year-old American -- a two-time winner this year -- is familiar with the Pinnacle Country Club course, having competed for the University of Arkansas. She has finished in the top five in each of her last five events. Last year, Taiwan\'s Tseng won her second consecutive Arkansas Championship with a four-foot birdie putt on the first playoff hole against Amy Yang. Two years ago, she closed with a final-round 65, including four birdies during a five-hole stretch on the back nine to win the tournament. Tseng, who has been No. 1 for the past 70 weeks, has won three of her seven events this season. After finishing 59th at the LPGA Championship earlier this month, Tseng said the pressure of being No. 1 was starting to get to her. \"I put too much pressure on myself,\" Tseng said. \"It\'s really hard to win every week, so now I want to smile more on the golf course, enjoy more on (the) golf course. I know if I\'m enjoying the course then people are going to enjoy watching me.\" Tseng leads the LPGA in tournament earnings this season, with more than $1 million while Lewis is second with more than $900,000. The 54-hole event begins Friday.