goal on April 5, 2013 against Viktor Fasth of the Anaheim Ducks. Playing in the first line along with Jamie Benn and Ray Whitney, Chiasson scored six goals in his first six games. Ottawa Senators Chiasson was involved in a blockbuster trade on July 1, 2014, being dealt to the Ottawa Senators along with Alex Guptill, Nick Paul, and a 2015 second round pick in exchange for star forward Jason Spezza, and Ludwig Karlsson. He scored a goal in his first game with the Senators on October 9, 2014. Following the 2014–15 NHL season Chiasson became a restricted free agent under the NHL Collective Bargaining Agreement. The Ottawa Senators made him a qualifying offer to retain his NHL rights and, on July 5, 2015, Chiasson filed for salary arbitration. Chiasson was seeking $2.4 million per year, while the Senators offered $1 million. The arbitrator awarded Chiasson a one-year contract of $1.2 million. Calgary Flames Following the 2015–16 season, Ottawa and Chiasson again clashed over a new contract, unable to agree to a dollar value. As such, the Senators traded Chiasson to the Calgary Flames in exchange for Patrick Sieloff on June 27, 2016. He was promptly signed as a restricted free agent to a one-year $800,000 contract with the Flames. He rebounded offensively with the Flames in the 2016–17 season, providing depth scoring with 12 goals and 24 points in 81 games. As an arbitration eligible restricted free agent following a first-round exit in the post-season, Chiasson was not extended a qualifying offer by the deadline on June 26, 2017. Washington Capitals On September 9, 2017, the Washington Capitals signed Chiasson, then an unrestricted free agent, to a professional tryout (PTO). Following training camp and preseason, on October 4, 2017, the Capitals signed Chiasson to a $660,000 one-year contract. Chiasson won his first Stanley Cup in 2018 with the Capitals. Edmonton Oilers On September 10, 2018, Chiasson signed a professional try out contract with the Edmonton Oilers, and on October 2, signed a one-year contract with the Oilers. With the Oilers, Chiasson set a new career high for most goals in a season, scoring his 14th on December 14, 2018, against Anthony Stolarz of the Philadelphia Flyers in a 4–1 victory. On April 26, 2021, Chiasson scored his 100th career goal in the NHL, opening the scoring in a 6–1 victory over the Winnipeg Jets. Vancouver Canucks On October 12,