With a 207 aggregate, Rosales stood 11 strokes behind Felton, who moved within 18 holes from winning the APGA Tours final leg with a 17-under 196.
Robert Pactolerin could only match par 71 and dropped to joint 23rd at 208 while Rodrigo Cuello and Cassius Casas were tied at 209 with five others after a 71 and a 69, respectively.
Mars Pucay, the other Filipino who survived the cut Friday, was at 55th place at 213 after a 71.
Felton, who fired a 60 in the second round, leads Scot Paul Lawrie, who moved in second at 198 after a 63.