UPDATE (1:20 p.m. ET): The Boston Celtics have officially re-signed Marcus Smart, the team announced Thursday afternoon. Terms of the contract were not disclosed.

“Keeping Marcus in a Celtics uniform was a top priority, and we’re excited to have accomplished that,” Celtics president of basketball operations Danny Ainge said in a statement. “His intensity is unmatched, and the level of toughness that he brings to the team throughout the course of the entire season is second to none.”

Smart’s reported four-year contract is fully guaranteed with no player options, according to The Athletic’s Jared Weiss.

ORIGINAL STORY: Marcus Smart finally is getting his payday.

The restricted free agent guard has agreed to a four-year, $52 million contract with the Boston Celtics, Yahoo Sports’ Shams Charania reported Thursday, citing league sources.

The $13 million-per-year deal is above the four-year, $46 million to $50 million window that Smart’s agent, Happy Walters, reportedly was negotiating in with C’s president of basketball operations Danny Ainge.

That Boston was willing to raise its price to keep Smart in town shows how much the team values the 24-year-old’s tenacious defense, hustle and playmaking ability, which mask his considerably subpar outside shooting.

Smart met with several teams, including the Brooklyn Nets and Memphis Grizzlies, in Las Vegas last week at the NBA Summer League, according to Charania. But he also had a private meeting with Ainge, who made “significant progress” with Smart’s agent, Happy Walters, in contract negotiations over the last few days, per Charania.

The two sides then met Thursday in Boston to finalize the contract. Smart’s deal makes him the only Boston player earning between $10 and $20 million next season, and as ESPN’s Zach Lowe points out, such a mid-level contract is a useful commodity on the trade market.

But for the present, keeping Smart — the Celtics’ longest-tenured player — allows the team to maintain continuity heading into a season that could stretch into June.

Thumbnail photo via Kim Klement/USA TODAY Sports Images