Rianne Mikhaela Malixi made double bogey for the second straight day but found a way to tame the tough South course and build a commanding 9-shot lead in the ICTSI Valley Golf Challenge in Antipolo, Rizal Thursday.

The 15-year-old amateur star became the first and only golfer to break par in the 72-hole championship layout, posting two-under-par 70 on the strength of six birdies.

Malixi completed 36 holes on even par 144, nine shots ahead of Harmie Constantino and Marvi Monsalve, her playing partners.

After a shaky 74, Malixi again bogeyed the opening hole but made a chipped-in birdie on the next hole.

Valley's South course had two of the toughest opening holes in the country.

After another bogey on the par-5 fifth hole, Malixi rebounded with birdies on 6 and 9 to get to 1-under at the turn.

She birdied 10 and bounced back from double bogey in the par-5 11th with back-to-back birdies from 12. She closed her round with five straight pars.

Monsalve shot a 78 to catch Constantino on 9-over.

She made the turn on 7-over after five birdies and a double, but steadied going home, picking up a birdie on 17, a par-5.

Constantino, who started the day tied with Malixi for the lead, struggled to save par and finished on 79.

She had eight bogeys through 16 holes before making her only birdie on 18.

Martina Marie Minoza turned in the second-best score — a 75 — to get a share of fourth place with Chihiro Ikeda on 10-over. Ikeda carded a 78.