Switzerland’s Mathilde Gremaud won gold in the women’s freeski slopestyle on Tuesday, dashing big air champion Eileen Gu’s dreams of a triple gold at the Beijing Winter Games. Gremaud, who took bronze in the freeski big air on her 22nd birthday and also collected silver in slopestyle in Pyeongchang, could not complete her final run, but an 86.56 score bagged in the second run ended up being enough for gold. United States-born Gu, who is competing for China, uncharacteristically went down in her second run, but managed to put together a solid 86.23-point third run to climb up to second and secu…