Matthews crossed the whitewash 14 times, two tries clear of his nearest challengers after 18 rounds of matches.
Club skipper Kyle Steyn presented Matthews with the trophy, as preparations continue for this weekend's URC semi-final clash with Munster at Thomond Park.
"It feels pretty good," said Matthews.
"I've said it quite a lot in the past, but a lot of my tries come from the hard work the boys in the back - and a few backs! - do at the set piece, so I've got to give thanks to them too.
"It's a great feeling to win the award, but you don't play the game for the individual prizes. It's testament to how hard we work as a squad to get the ball over the line, and long may it continue!"