PGA: Valspar Championship - Final RoundMar 11, 2018; Palm Harbor, FL, USA; Paul Casey poses with the trophy after winning the Valspar Championship golf tournament at Innisbrook Resort - Copperhead Course. Jasen Vinlove-USA TODAY Sports
Woods, who finished one stroke behind Casey, lamented a "couple of putts here and there" that could have led to his 80th PGA Tour victory.
His solid performance, however, provided further proof that he is a force again after last April's spinal fusion surgery on his lower back.
"Unfortunately I just didn't quite feel as sharp as I needed to with my irons, played a little conservative because of it," Woods told reporters at Innisbrook Resort in Palm Harbor. "It showed in my amount (two) of birdies today.
"I've been here before a few times, so I felt very comfortable. As a whole I felt very good about what I did this week."
The old Tiger magic was mostly missing on Sunday as the 14-times major champion tried to record his 80th PGA Tour victory, and his first since 2013.
Missing, that is, until the par-three 17th, where Woods perfectly read and then executed a 43-foot birdie putt, his ball curling deliciously into the centre of the cup as the gallery went berserk.
But Woods could not replicate the magic at the par-four 18th, where he missed a difficult 40-foot birdie putt that would have forced a playoff with Casey.
Woods carded 70 and had to settle for second with fellow American Patrick Reed (68), who made an embarrassing bogey at the last when his first putt, through the fringe, failed to make it up the hill and rolled all the way back to his feet.
When the dust settled, Casey, long in the clubhouse with a 65 for 10-under 274, could finally celebrate his second victory on the PGA Tour.
"Probably not the most significant win of my career, but it's certainly one of the most satisfying ones, the quality of the golf I played," said Casey, who has also won 13 times on the European Tour.
"I know I made some errors yesterday -- I hit it in the water twice -- but as a whole I would say it's one of the cleanest weeks I've ever had from kind of a golf course management point of view."
Woods, meanwhile, kept his eye on the long game as he prepares for the April 5-8 Masters at Augusta National.
"I believe my game is progressing," he said. "I had really some nice building blocks at Honda (equal 12th two weeks ago) and I've had a few tweaks for this week and it paid off.
"Just a couple of things with my set-up and I was just trying to get my posture organised a little bit more ... little things (that) just make for better passes through the golf ball."
(Reporting by Andrew Both in Cary, North Carolina; Editing by Ken Ferris/Peter Rutherford)