Canizares earned his first victory on the Senior Tour as he posted a 4-under 67 in Sunday's final round.
'This is the longest playoff I have ever been in,' Caizares said. 'I think my longest playoff was six holes. You get tired when it is this long.'
Canizares had to sink a 10-foot birdie putt on the final hole in regulation, a par-five, to force the playoff with Morgan, who shot up the leaderboard with a 7-under 64 on Sunday in Newport Beach, Calif.
The 54-year old Spaniard missed several chances earlier in the playoff before sinking the 24-foot winning putt worth $210,000.
Morgan missed his birdie attempt on the ninth playoff hole from 40 feet out, leaving it short about 6 feet. Caizares then followed with his winning putt.
'It is very nice to win because I am playing with some of the best players in the world,' Caizares said. 'And in golf you have 18 holes, so I think you always think you have a chance to win.'
Defending champion Allen Doyle finished alone in third at 10-under while Hale Irwin, Dave Stockton and John Bland shared fourth at 9-under-par.
Terry Mauney, the overnight leader, struggled badly on Sunday as he carded a 6-over 77 and tied for 10th at 6-under 207.
See Full-Field scores from the Toshiba Senior Classic here.