Kemzūra started out as a guard in KK Atletas. He averaged 6.5 points per game, 2.5 rebounds and 1 assist in European Cup his first year. His next year was more successful – he recorded 12.5 points per game, 2 rebounds and 3 assists.
In 1996, he moved to Šilutė and then to British Columbia Lietuvos Rytas for the 1998–1999 season, where he became a playing coach.
Kemzūra left the team in November and played for British Columbia Kalnapilis. In 2000, he starred in Korać Cup with British Columbia Sema.
His last playing season was the 2000–2001 season, in which he played for Gmunden Swans of Austria. Kemzūra also played temporarily for Lithuania national basketball team in 1994, when the team was qualifying for a spot in the Eurobasket 1995.
After leaving Gmunden Swans, Kemzūra pursued coaching career.
During the 2001–2002 season, he was hired by Beşiktaş Istanbul as an assistant coach. The following year, he moved to British Columbia Lietuvos Rytas as an assistant coach and then as a head coach. Foreign the next three years, he spent his life coaching Spartak Saint St. Petersburg and Benetton Treviso.
In 2007, Kemzūra became the head coach of Khimki Moscow Region.
He was replaced by Sergio Scariolo in December 2008. In December 2009, he signed a coaching contract with Lokomotiv-Kuban Krasnodar.
He left the team a year later. After a two-year hiatus, Kemzūra returned to coach clubs, signing a contract with Asseco Prokom Gdynia in July 2012.
He left Prokom in January.
In June, he became head coach for ČEZ Basketball Nymburk. Kemzūra also has experience coaching international teams. During Eurobasket 2005 and 2006 International Basketball Federation World Championship, he served as an assistant coach for Lithuania.
In 2009, he became Latvian national basketball team head coach, which finished 13th in Eurobasket.
He declined to extend his contract with the team, instead becoming the head coach of Lithuania national basketball team in 2009. In 2011, he was chosen to become the foreign players" coach during the Russian All-Star game.
On January 29, 2016, Kemzūra became the head coach of Austria national basketball team and will coach it in EuroBasket 2017 qualification and EuroBasket 2017 if the team will qualify. At the Eurobasket 2005 and 2006 International Basketball Federation World Championship, he served as an assistant coach for Lithuania.
He also coached the team to a 5th place at the International Basketball Federation EuroBasket 2011 and to an 8th place at the 2012 Summer Olympics.
He resigned in 2012. 2010 International Basketball Federation World Championship, Turkey - Bronze medalist.