Utriainen was born in Nokia, Finland on 5 February 1991.[1] Her father, Esa Utriainen, was Finnish champion in men's javelin throw in 1979 and represented Finland at the 1983 World Championships.[2] Sanni Utriainen first broke 50 metres in 2008, throwing 51.89 m at the Pihtipudas Javelin Carnival and winning the Finnish youth championship with 51.00 m.[3] In 2009, she placed ninth at the European Junior Championships in Novi Sad, throwing 51.25 m in the qualification and 48.45 m in the final.[3]
At the 2010 World Junior Championships in Moncton Utriainen won gold, throwing a personal best 56.69 m on her final attempt to overtake Latvia's Līna Mūze by five centimetres.[4] Later that summer she won gold at the Finnish championships in Kajaani, throwing 56.29 m for her first (and, as of 2015[update], only) national senior title; she also won at the Finland-Sweden Athletics International, setting a new personal best of 57.26 m.[3]
In the following years Utriainen's results stagnated; although she improved her personal best in each of 2011, 2012 and 2013, the improvements were only minor, and she didn't reach the international elite.[3][5] Her best throw in 2012, 59.31 m, was a Finnish under-23 record and exceeded the B standard for the Olympics in London;[6] she was selected for the Olympics, but went out in the qualifying round, not registering a valid mark on any of her three attempts.[1] In 2013, she improved her national under-23 record by four centimetres to 59.35 m.[3] She missed the 2014 season almost entirely due to an elbow injury.[5]
Utriainen broke 60 metres for the first time in June 2015 in Lappeenranta, throwing 60.08 m.[7] At the 2015 national championships in early August she only managed 57.59 m and placed second behind Oona Sormunen, but the following week she threw 63.03 m in Kuortane, improving her personal best by almost three metres and exceeding the qualifying standard for the World Championships in Beijing.[5][8]
Coaching
Utriainen is coached by her father Esa.[9] Former javelin thrower Tero Järvenpää became her secondary coach in 2015.[10]