After the elimination, team management vacated all the Sharks' captaincy positions, including Thornton's role as one of the alternate captains. Prior to the 2010–11 season, he was chosen to replace the retiring Rob Blake as the eighth captain in team history on October 7, 2010. Nine days later, he signed a three-year, US$21 million contract extension with the Sharks. Near the start of the 2010–11 season, Thornton scored the fourth hat-trick of his NHL career against Martin Brodeur in a 5–2 win over the New Jersey Devils. In November 2010, Thornton was suspended two games for a controversial hit to the head against St. Louis Blues forward David Perron. Perron missed the remaining 72 games of the 2010–11 season due to post-concussion syndrome. He returned after missing 97 games over 13 months (394 days) on December 3, 2011. Later in the campaign, Thornton eclipsed Marleau as the Sharks' all-time leader in assists. Thornton scored his 1,000th career point with a goal in a game against the Phoenix Coyotes on April 8, 2011. In the first round of the 2011 playoffs, Thornton scored the series-winning goal in overtime of Game 6 against the Los Angeles Kings to advance the Sharks to the second round.