Danny Willett had lost both his opening matches in Group 11 at Austin Country Club in Texas before defeating Knox 4&2 to kill off the Scot’s hopes of progressing to the last 16 in the £7.8 million tournament.
The loss denied Knox a place in a play-off to determine the winner of the bracket after American Bill Haas beat Korea’s KT Kim by the same margin in the other match to leave that pair both sitting on two points.
It was the second year in a row that Knox had bowed out after the group stage, his exit on this occasion coming despite the 17th seed beating six-time PGA Tour winner Haas 3&2 in the opening round of matches.
He never managed to get his nose in front against Willett, who was always in the driving seat from going two up after seven and twice responded with birdies after his opponent had won holes on the back nine.
Having decided not to play in next week’s Shell Houston Open, Knox, who is flying the Saltire in the Masters along with former winner Sandy Lyle, will hope he can use some time on the range to try to get back firing on all cylinders again for the season’s opening major.
Alex Noren, the reigning Aberdeen Asset Management Scottish Open champion, had already won through to the last 16 and the Swede was joined by Phil Mickelson, the winner of the same event in 2013.
Mickelson, who also became Open champion, of course, the same year, made it three wins out of three with a 6&5 victory over JB Holmes, having earlier handed out similar thumpings to Si Woo Kim and Daniel Berger.
Elsewhere, four Scots – Chris Doak, Craig Lee, Bradley Neil and David Law – successfully made the cut in the Barclays Kenya Open, the first event on this season’s Challenge Tour.
After rounds of 66 and 70 at Muthaiga Golf Club in Nairobi, Doak is joint ninth on six-under, six shots behind Adrien Saddier after the Frenchman moved into pole position having carded an eagle and seven birdies in a scintilating 62. “It was a bit up and down today,” said Doak. “I hit a few bad shots and also didn’t really take advantage of the good ones I hit.”
Lee is two shots further adrift, having seen his good work over 32 holes – he’d not dropped a single shot in getting close to the lead on eight-under – undone by a sore finish. He ran up a double-bogey six at the sixth, partially repaitred that damage with a birdie at the next before finishing bogey-bogey.
“That is going to hurt quite a bit going into the weekend,” admitted the 39-year-old, who is playing in his first event since agonisingly losing his European Tour card by a single spot at the end of last season.
Both sitting on two-under, Neil posted an excellent four-under 67 while Law shot 69, each carding eagle-3s at the tenth. Ross Kellett was the odd man out among the five Scots in the field, missing the cut by four shots after rounds of 75 and 71.
Meanwhile, Colin Montgomerie has won the European Senior Tour Shot of the Year award for the second year running. The Scot’s effort from an awkward spot in a bunker on the 12th during the final round of the KitchenAid Senior PGA Championship at Harbor Shores secured 29 per cent of the vote. Montgomerie described the shot as being “tricky from a tough lie”.