The petition lacks merit. The procedural issue raised by Micronesia, et al. deserves short shrift. It is axiomatic that the CA has discretion to grant a motion for extension provided that it beinterposed within the original filing period.[11] Cantomayor had until April 9, 2002 (April 8, 2002 being a holiday) to file a petition for certiorari but on said date he filed a Motion for Extension[12] of thirty (30) days or until May 9, 2002 to file his petition. He actually filed said petition on April 30, 2002. The timeliness of said petition was never questioned by Micronesia, et al. before the CA, not even in their Motion for Reconsideration from the September 13, 2002 CA Decision. The petition was therefore properly given due course by the CA.   Going now into the substantive matter raised by Micronesia, et al., we note that the LA denied the claim of Cantomayor for permanent and total disability compensation based on the finding that his ailment was a pre-existing condition. The LA explained:   It is undisputed that complainant was repatriated to the Philippines due to coronary disease he suffered while employed as a seafarer abroad. Back home, he was confirmed to be suffering from coronary artery disease [in] 3 vessels and needed a bypass surgery. In fact, the findings of the hospital in Italy show that complainant suffered occlusions in three vessels, one ranging from 70% to 100%, the second 100%, and the third 80%, all of which indicate that two of the said vessels were almost completely blocked while the third has been reduced to 20% capacity. This [sic] findings prove that complainants ailment was already in an advanced stage affirming the fact that the illness was not an overnight occurrence but already a pre-existing condition.[13] The NLRC found no taint of grave abuse of discretion in the foregoing decision of the LA.   The CA overturned the NLRC and LA and held that the coronary artery disease which afflicted Cantomayor during his employment with Micronesia, et al. caused