By the time the 2016–17 season had started, Chára was skating as part of the Bruins' top defensive pairing beside 6-foot-5-inch rookie defenceman Brandon Carlo, nearly 20 years younger than him. A similar "pairing" for Chára occurred as the 2017–18 season got going: the American-born star rookie defenceman Charlie McAvoy had, by mid-November of the new Bruins season, become Chára's latest "regular" defensive partner for the Bruins. By early February 2018, Chára played in his 1,400th NHL game in a 4–1 home ice defeat of the Toronto Maple Leafs, only the 39th player in NHL history to reach the milestone. On 28 March 2018, the Bruins re-signed Chára to a one-year, $5 million contract extension. On 17 April 2019, in game 4 of the first round series between the Bruins and Toronto Maple Leafs, Chára became the oldest defenceman in NHL history to score a game-winning goal in the Stanley Cup playoffs. On 9 June 2019, during game 6 of the 2019 Stanley Cup Finals against the St. Louis Blues, Chára scored an empty net goal and as a result became the oldest defenceman in NHL history to score a goal in the Stanley Cup Finals.