On 6 February 2010, Vlašić cleared 2.06 m in Arnstadt, Germany. The victory at the Hochsprung mit Musik added one centimetre to her own personal best and Croatian record and brought her to third on the all-time indoor lists behind Sweden's Kajsa Bergqvist (2.08 m in 2006) and Germany's Heike Henkel (2,07 m in 1992). A month later, she retained her world indoor title in Doha with 2.00 m, winning ahead of Spain's Ruth Beitia and USA's Chaunté Lowe, both jumping 1.98 m. Through the outdoor season, she wins the first edition of the IAAF Diamond League by winning the seven meetings in the event. She and her main rival of the season Chaunté Lowe both led the circuit. Vlašić cleared 2.00 m on six out of seven occasions in the circuit.