The present invention is directed to a peel-open, non-reclosable package formed from a single thermoplastic laminate comprising a first film laminated to a second film by a lamination film or lamination layer. The package includes a peelable heat-seal seam adhering an interior surface of a first sealing section of the interior package surface to an interior surface of a second sealing section of the interior package surface. The package also includes an asymmetric cross-sectional seal interface formed at the peelable heat-seal seam by disjoining a segment of the first film from the first sealing section prior to heat sealing the first and second sealing sections together.