Learner Tien continues making history. At 20, the Irvine native is the youngest American man to reach the US Open fourth round since Andy Roddick in 2002 and the youngest American man to reach the second week of both hard court Grand Slams since Palos Verdes’ Pete Sampras in 1990. 📸 of Learner: Shea Kastriner/USTA #USOpen #TeamSoCal #SoCalTennis