The 45-year-old formed a fearsome partnership with the Swede during his time at Parkhead, with the pair winning two league titles and two Scottish Cups while starring up front together.
The duo were eventually broken up when Larsson left Glasgow in 2004, joining Barcelona on a free transfer. Hartson would depart for West Brom two years later.
Reminiscing about his playing days during an interview with talkSPORT, the Welshman was quick to single out his old colleague for praise.
"In terms of my favourite [strike partner], I would have to say Henrik Larsson”, he said.
"He was a phenomenon.
“People question that a lot of his goals came in the Scottish league, but he went to Manchester United and Barcelona, won a Champions League.
“He broke all sorts of records for his country, played in three World Cups, and he had a bit of everything.
"I loved playing with them all – Craig Bellamy, Dion Dublin, Mustapha Hadji – but my favourite would have to be Larsson because he was so special.”
Larsson joined the Bhoys from Feyenoord in 1997, arriving in Scotland on a free transfer. He went on to win four titles at Parkhead, and was top scorer in the Scottish Premiership on five occasions.
He hung up his boots in 2009 after one last stint with Swedish side Helsingborg, and also enjoyed a brief loan spell with Manchester United in 2007, helping them to a Premier League title.