On March 16, 2018, Kane scored his first NHL hat-trick against the Calgary Flames, and then later added a fourth goal, contributing more than half the goals in the Sharks 7–4 win. On April 26, 2018, Kane received a one-game suspension for cross-checking Vegas Golden Knights forward Pierre-Edouard Bellemare during Game 1 of the Western Conference semi-finals. Through nine playoffs games, Kane recorded four goals and five points. On May 24, 2018, the Sharks re-signed Kane to a seven-year, $49 million contract worth $7 million annually. Kane has said that he would like to remain with the Sharks for the rest of his career. During the 2018–19 season, Kane had the second highest point total of his career, as well lead the NHL in penalty minutes with 153. During the 2019–20 preseason, Kane was suspended three games for abuse of officials. Two games after his suspension, Kane became the first Sharks player in franchise history to record a first period hat trick in a 5–2 win over the Carolina Hurricanes. Kane recorded another natural hat trick later that season when the Sharks visited the Washington Capitals on January 5, 2020, scoring three straight goals in just over 10 minutes during the second period in a 5–4 overtime loss. After an elbowing hit in a game against the Winnipeg Jets on February 14, 2020, Kane was suspended for three games. On August 1, 2016, Kane pleaded not guilty to one count of criminal trespassing and four counts of non-criminal harassment after confrontations with four separate people at a downtown Buffalo bar in June 2016. At that time, Kane was a member of the Buffalo Sabres. According to a police report, Kane became involved in a fight with a bouncer at a bar called Bottoms Up, after allegedly grabbing an unnamed woman by the throat and attempting to force her into a car outside the nightclub. A second police report alleged that, in a separate incident, Kane grabbed a woman by the arms inside the nightclub and attempted to force her outside. Kane surrendered to Buffalo police in late July 2016. Said Sabres GM Tim Murray of the incident, "Whether he has done these things or not, or he's guilty of these things or not, it's not something I like getting up in the morning and reading about, that's for sure." The incident came after another incident in February, in which Kane was suspended by the team for missing a practice after attending the NBA All-Star Game in Toronto.