What’s most interesting about Riccardo Tisci’s approach to couture is that he rejects the haute genre’s traditional ladyfied ways in favor of a next-generation sportswear approach. It was a bold stance to take when he arrived at Givenchy, one he has developed with distinction into something that now seems worthy of the couture mantle. On Tuesday, under the guise of “A Trip to Machu Picchu,” Tisci invoked a vaguely Incan influence as the conduit for an impressive, audacious collection. He offered abundant sportif in demonstrative pilings of outerwear over relaxed pants and skirts, in denim as well as tonier fabrics, or a big silk bomber and chill-chasing chinchilla hood atop a languid dress. His palette of browns and khakis, lightened here and there with shots of pink, lent a nice unfussy modernity, though a few of the weightier fabric mixes might have benefited from similar variations. To wit, “skirt in woven yak hair” are not appealing words to read in a sweltering venue overfragranced with incense. More often, however, the clothes worked beautifully, from lovely new versions of Tisci’s ropy goddess dresses to a pair of rounded Icelandic sweaters. As for his fringing, you had to love the curious, wild red tunic affair that played, surely unintentionally, like a left-field tribute to Liza.