Tom Winter, 31 and from Lower Penn, took up running after his father Ian died of Alzheimers earlier this year but last week recorded a time of three hours and 38 minutes running the 26.2 miles needed to complete a marathon.
Tom's family and friends joined him on the run to give him support and encouragement as he ran around the streets of Wolverhampton.
He said: "My father was a great guy and he has been a big miss for me and my family. During lockdown I got into running for my own sanity and really enjoy it.
"I wanted to raise some money for the Alzheimers Society so thought running a marathon on my dad's birthday would be a great way of doing it.
"I only wanted to raise £500 but we have gone past £3,000 already, people have been so generous."
Running through the streets of Wolverhampton with his friends and family will last long in his memory.
He said: "I started and finished at my house and people came and either cycled or ran with me, it was wonderful and without all my family and friends there it would have meant nothing.
"I am thinking about doing one of the big marathons next year."
Tom's partner Hayley Willets is proud of her pace-setting boyfriend.
She said: "His time was just incredible, there is no way I could have kept up with him. To raise so much money for charity is incredible, and the total keeps rising."
To donate towards Tom's fundraising visit justgiving.com/fundraising/marathonforianwinter.