Ueda, the 2007 Japanese tour money leader playing in her fourth season on the U.S. circuit, moved to 5-under 139, three strokes behind South Korean leader Kim In Kyung.
Kim finished off her round of 73 with a birdie to lead Michelle Wie and world No. 1 Yani Tseng by one at Siam Country Club.
‘‘To be honest, I didn’t expect much of myself since I didn’t feel good about my shots in morning practice, but I just putted really well,’’ Ueda said. ‘‘I chipped in for birdie on the third and made a long birdie putt two holes later. That made things easier for me.
‘‘I want to win, of course, when I get a chance. But for now I’d like to stay focused on establishing my golf.’‘
Ueda struggled for most of the 2010 season and finished 46th in the money rankings.
Of the other two Japanese in the field, defending champion Ai Miyazato recovered well from her opening 75 to shoot a 69 and climb into a tie for 25th at even-par 144.
‘‘I got back my swing rhythm after I did my routines slowly,’’ said the six-time winner on the tour. ‘‘I stayed aggressive and birdied the 18th. If I can control myself, I can play well like today. I still have a chance to finish high on the leaderboard, so I’ll continue to try my best.’‘
Mika Miyazato, who shared 11th place with Ueda after the first round, only managed a 72 that left her in a group tied for 14th at 2 under.