The Australian narrowly made the cut when the second round was finally completed on Saturday, making birdie at his last hole to move into a tie for 50th place.
From there he was virtually unstoppable. He was perfect on Sunday on his way to a 64 that could have been even better, and was nearly as flawless on Monday, playing his opening nine in 31 strokes to move into a share of the lead.
He bogeyed the first and third playoff holes to finish three strokes behind eventual champion Johnson, but after enduring everything he has this year, he was still upbeat following the loss.
“I've just finished second in the Open. Yeah, I could have won it, but look, we spoke about it earlier this week, my perspective is quite good at the moment,” said Leishman, whose wife, Audrey, was given a 5 percent chance of living after being diagnosed with a rare life-threatening bacterial infection known as toxic shock syndrome just before the Masters.
“I can go home tomorrow and hug Audrey and the boys and celebrate a little bit. It would have been nice to have a claret jug to drink out of to celebrate, but I'll find something else.”