Wi has won nine times in Asia, but never on the PGA Tour. His best showing in the United States has been a tie for second at last year's Valero Texas Open, which will be next week's stop on the PGA circuit.
Jay Williamson, Nathan Green, Parker McLachlin, Charles Warren, John Merrick and Eric Axley shared second place at 67.
Kenny Perry, who bogeyed the final two holes of regulation and then lost in a playoff two weeks ago at the Masters, returned to action with a 3-under 69 that left him tied for 19th place. He got it to 5-under before suffering bogeys at the 15th and 17th holes of the TPC-Louisiana course.
"I did lose focus a little bit and kind of thinking a lot about two weeks ago and what was going on," Perry said. "I mainly got tired mentally, which got me tired physically. Even though I was 5-under par, it just seemed like I was really wearing down by the end of the day."
Current U.S. Amateur champion Danny Lee, playing his first tournament as a professional, shot a 4-over 76. Defending champion Andres Romero had a 73.