The Hollywood star said Emma Fogarty – who is Ireland’s longest survivor with the genetic condition epidermolysis bullosa (EB) – is “what courage is all about”.
Born with no skin on her left foot and right arm, Miss Fogarty experiences excruciating blisters from the slightest touch – a condition also known as butterfly skin.
Farrell, 48, finished the 42km (26-mile) run in four hours, six minutes and 45 seconds.
Each of the final four kilometres of the race represented a decade of Miss Fogarty’s life. Now aged 40, doctors originally told her parents she’d be unlikely to live longer than a week.
Their Run To 40 campaign to raise funds for Debra, the national charity supporting people living with EB, initially had a €400,000 target (£333,000) but they now aim to achieve €1m (£833,000) after viewers of the Late Late Show donated €470,000 (£391,000) last week.
The tally now exceeds €694,000 (£578,000).
‘Nothing compared to the pain she faces every day’
Oscar-nominated Farrell, who’s currently starring in Sky Atlantic’s The Penguin, said after the pair crossed the finish line at Upper Mount Street just before 1pm on Sunday: “I have known Emma for many years and she epitomises bravery, she is what courage and pure determination are all about.
“That run was nothing compared to the pain she is forced to endure every single day, even though she doesn’t show it.
“It was an honour to see her waiting for me with 4km to go, each of those representing a decade of her life, and to do the final stretch together. I’ll never forget it.”
Miss Fogarty, who lives with the most severe form of EB, said she was determined to celebrate her 40th birthday in June in dramatic fashion because others with her form of EB rarely live beyond 35.
She said: “This was a dream come true for me and I want to thank Colin, who has been the most supportive, generous and loyal friend I could wish for.
“He has always shown his compassion and empathy for people living with EB and is a true champion in my eyes.
“Running a marathon is never easy but once he committed to it there was no going back, he is a man of his word.”
‘Reaching 40 shouldn’t be a miracle’
EB is caused by a lack of proteins between the skin layers, meaning even the mildest touch can cause devastatingly painful blisters, which must be bandaged, causing more extreme pain.
Some 80% of Miss Fogarty’s body is covered in layers of bandages to prevent wound infection.
“The doctors said it would be better for me not to make it because my life would be so hard,” Miss Fogarty said.
“No one expected me to survive for this long – because people with my type of EB almost never do – but I’ve always been encouraged to be a fighter.
“Reaching 40 shouldn’t be a miracle, but right now, it is.”
Miss Fogarty has also had two battles with cancer.
Funds raised during the Run To 40 campaign will be used to fuel pioneering research into EB in Ireland.
Around 22,500 runners took part in the Dublin Marathon, with the race won by Kenyan Moses Kemei with a personal best time of two hours, eight minutes and 47 seconds.
