Mick Somerset, 75, from Parson Cross, was fishing at a private lake in north Sheffield when he fell into the water.
Fellow angler Darren Grayson, 41, from Wincobank, heard the splash and saw non-swimmer Mr Somerset frantically trying to keep his head above the water, before he lost consciousness.
Without a thought for himself or the £700 mobile phone in his pocket, Mr Grayson, a steel plant driver with three-year-old twin boys, jumped into the water and dragged Mick to safety.
The pair met up again at the fishing lake after the drama, where Mr Somerset, now fully recovered from his ordeal, thanked Mr Grayson for saving his life.
Mr Somerset said: “I owe Darren a huge debt. If he hadn’t been fishing that day I would not be here to tell the tale.
“I slipped in and can’t remember anything else until he was pulling me out of the freezing water.”
Mr Grayson said: “I didn’t think about anything other than getting Mick out. I did what any caring person would have done.
“I’m just glad Mick is back fishing again.”
Mr Somerset’s son, Richard Somerset said: “Without any thought for his own safety, Darren ran and jumped in the lake to try and save my dad.
“Darren, who has only just joined the lake so did not know how deep the water was and if there were any underwater dangers, managed to grab my dad before his clothing lost all the air pockets and my dad sank and ended up dead.
“This incident has really frightened my dad as he knows he would not be alive now if it were not for the brave actions of Darren.”