On Sunday at the Scottish Open, Fox hit his tee shot deep into some gorse at the par-3 sixth at Dundonald Links.
"I found myself particularly on the back nine, just a little bit mentally tired", said Dodt.
The pair returned to the 18th for sudden death and Cabrera Bello, whose closing 64 had set a new course record at Dundonald Links, produced a stunning approach to the par five to set up a two-putt birdie.
Both men found the middle of the fairway on the first play-off hole, but Shinkwin, who was up first, yet again pushed his approach shot left of the green in nearly a carbon copy of the shot he'd hit around 20 minutes earlier.
"I was very happy, I really gave it a go in the playoff and it worked out for me". "Obviously a few months back, things were pretty hard, but life's a little bit easier right now and obviously I'm enjoying my golf".
"I'd have signed for that score if you'd offered me it before I went out", said Poulter.
Dodt's challenge for the title faded after four bogeys on the back nine and he finished in a tie for fourth on eight under with a 73, although he took the third Open spot, edging out England's Anthony Wall by virtue of his higher world ranking - 193 to 245.
It meant a play-off against Ryder Cup Spaniard Rafa Cabrera-Bello, who took advantage of his unbelievable good fortune to notch a winning birdie at the first play-off hole and claim his third tour victory.More news: Naz Baloch joins PPP, parts ways with PTI
He will be joined at Royal Birkdale by compatriot Michael Hendry.
"I've won before and I have been up there so many, many times, and things not really working out for myself".
Hopefully, Shinkwin will get over his 15 minutes of madness and draw on all the brilliant golf he played.
France's Mattieu Pavon finished third on 10 under after a final-round 66, a position that also qualifies him for Birkdale along with Australia's Andrew Dodt, who gets his first shot at a major. I think more than anything else - you can beat yourself up before you get on the golf course, which is a problem.
"I kind of knew I had to hole that".
"And to now being playing in my first Open, my first major and in my first full season is going to be very special and I am very happy".
Poulter was seeking a 14th worldwide win - and first since November 2012 - but was always playing catch-up after three-putting Nos.
Even earlier, Open champion Henrik Stenson's final competitive round before beginning the defense of his title ultimately ended in rather downbeat fashion.