Purchased at the 2017 December Tattersalls sale, Santa Monica shipped overseas to begin a training regimen under the guise of Chad Brown. Running under the partnership of Mrs. John Magnier, Madaket Stables LLC and Deron Pearson, she won impressively in her U.S. debut at Keeneland followed up by a third-place finish in the G2 Sheepshead Bay and a win in the G2 Dance Smartly at Woodbine on Queens Plate Day. She was sold privately to R Unicorn Stable at the conclusion 5-year-old season.