On a day when Matsuyama overturned a five-shot deficit on the back nine to land his eighth title triumph on the US circuit, Knox finished in a tie for seventh at Waialae Country Club in Honolulu.
The 36-year-old Scot signed off with a bogey-free five-under 65, having leapt up the leaderboard on the back of an equally-impressive 64 on Saturday, to end up on 17-under.
It was Knox’s best effort - he’s now recorded 24 top 10s on the PGA Tour - since finishing in the same position in the AT&T Pebble Beach Pro-Am last February.
As a result, he’s up to 255th - a jump of 46 spots - in the updated world rankings, which see Scottish No 1 Bob MacIntyre sitting 58th heading into his first event of 2022 in Abu Dhabi this week.
Matsuyama, who started the final round two shots behind Russell Henley, found himself five adrift after the American stormed to the turn in 29.
But, as the birdies suddenly dried up for Henley, Matsuyama stormed home in 31 for a closing 63 to force a play-off as the pair finished locked together on 23-under.
Matsuyama then claimed victory in style as he eagled the first extra hole, the win seeing him move level with Korea’s K.J. Choi for most victories on the PGA Tour by a player from Asia.
The Japanese player also becomes first two-time winner this season after landing the ZOZO Championship on home soil in October.
“I feel great,” said Matsuyama afterwards. “To win here where the first Japanese player in Isao Aoki won on the PGA Tour is extra special.
“Especially on a course that I haven’t really played that well. It’s a tough golf course for me. I’m extra excited, extra happy because of that.”
The win lifted Matsuyama into top spot in the FedEx Cup while he’s up nine places to 10th in the world rankings,
Ireland’s Seamus Power (65) finished in a tie for third alongside American Kevin Kisner (64) on 19-under.