The 31-year-old striker, who now plays for MLS side Columbus Crew SC, took to Twitter on Saturday afternoon to congratulate former teammate Albert Adomah and the club after their 1-1 draw with promotion rivals Brighton & Hove Albion at the Riverside Stadium secured them a spot back in the Premier League for the first time since 2009.
Both teams began the day knowing that victory would see them join champions Burnley in the top-flight next season, but Boro needed just a point to pip the Seagulls to second place on goal difference.
Aitor Karanka’s men took the lead in the 19th-minute when Christian Stuani netted his seventh Championship goal of the season, but Dale Stephens pegged them back 10 minutes after the break with a set-piece header to set up a tense final half-hour.
Stephens was dismissed for a foul on Christian Ramirez soon after his goal, however, as the hosts made the man advantage count and closed out the game, prompting an outpouring of tributes on social media from the likes of Kamara.
Kamara originally joined Boro from MLS side Sporting Kansas City in September 2013 for around £900,000 and made a hot start to life on Teesside, scoring four goals in his first eight appearances for the club.
However, injuries later took their toll, and after failing to find the back of the net over the rest of the season, the Sierra Leone international found himself out of favour with Karanka heading into the 2014-15 campaign
Those circumstances soon prompted him to cancel his contract at the Riverside and return to MLS to re-join his first professional club Crew SC, where he has since been making up for lost time up in clinical fashion.
The towering front man scored a joint-league-leading 22 goals in 32 regular season appearances last term to finish as MVP runner-up to Toronto FC forward Sebastian Giovinco, before netting four more times in the playoffs as his side made it all the way to the MLS Cup final, only to be beaten 2-1 by the Portland Timbers on home soil.
Gregg Berhalter’s side have since endured a slow start to the 2016 campaign, having taken just nine points from their opening nine games, but Kamara himself has still managed to grab five goals in the meantime.