Mattia Gavazzi's father, Pierino Gavazzi, was also a professional rider. He won a stage at the 2004 Girobio, the version of the Giro d'Italia for young amateur riders. He turned professional in 2006 for, but joined the team midway through the season. Following several good performances, he was signed by for the following year. He secured six victories with them in 2007, including three at the Tour de Normandie, showing his talent as a sprinter. In 2008 he remained with the same team, who became known as. In February he achieved a second place in a stage of the Giro della Provincia di Grosseto, behindDanilo Napolitano and in front of Filippo Pozzato. The following month he was again second at the Settimana Internazionale di Coppi e Bartali, beaten by Francesco Chicchi. In April, he won a stage of the Settimana Ciclistica Lombarda, and in May the Giro di Toscana, beating Chicchi. 2009 saw him sign for with immediate success. He won a stage at the Tour de San Luis and dominated at the Tour de Langkawi, winning four stages and the Points classification. In 2010 he switched to and scored his first victory of the year at a Settimana Ciclistica Lombarda stage in early April. However, a urine sample taken two days previously tested positive for the presence of cocaine, and this triggered a suspension by the sport's governing body. He had previously tested positive for cocaine, and received a 14-month suspension, as an amateur in 2004. Gavazzi made his return at the 2013 Tour de San Luis, where he won the last stage by out sprinting Slovak Peter Sagan. In April, he won the Giro di Toscana, a hilly race where he edged Ivan Rovny and Taylor Phinney in the sprint. At the end of the 2013 season, Gavazzi terminated his contract with. Androni team manager Gianni Savio claimed that the split was due to Gavazzi demanding a guaranteed start for the 2014 Giro d'Italia. Gavazzi signed with the team for the 2014 season. On 12 April 2016, it was announced that Gavazzi had been provisionally suspended by the UCI for a cocaine positive taken at the 2015 Tour of Qinghai Lake. It was his third positive test to this substance during his career. He was given a four-year suspension, backdated to July 2015.
