The married man in his 40s had been drinking into the early hours with pals after the televised matches finished and decided to walk back to his hotel after being advised not to drive.
It is believed he lost his bearings in the freezing conditions and wandered on to the lake not realising it was iced over and covered in snow and fell through after 20 yards.
His wife woke in the morning at the world famous country club in Frimley Green, Surrey, and when she realised he had not returned raised the alarm and the grounds were searched.
The man was spotted under the ice close to the bank and fire crews and police raced to the scene and recovered the body and paramedics tried to revive him on the way to hospital.
However waiting doctors pronounced the tragic darts fan dead.
It is understood the husband regularly visited the World Darts Championships which are currently being televised on BBC with a group of pub pals and their wives.
His body was found in the frozen ornamental lake nine hours after he was last seen alive at 2am walking back.
A Lakeside Country Club source said: "The lake is only about 20 yards away from the door and he must have walked out and straight on to the lake thinking that he was walking on land.
"He walked in an arc shape judging by the footprints and was nearly back on dry land when he went through. The ice must have given away and in those temperatures you won't survive long.
"It must have been about -8C to -10C last night and drink had been taken and tragically he could not get out."
Fire Brigade Watch Manager Karl Bowen said he was told the victim had been drinking while watching the darts.
He said: "Apparently he had been told not to drive his car which was parked and had then gone to walk it instead and the last time that anyone recalls seeing him alive was at about 2am.
"The body was so close to the side of the lake that police had already pulled him out - all we could do was help put him on a stretcher and get him into an ambulance for him to be worked on.
"The man had taken a walk and may have not known there is a lake there because it was frozen and covered in snow.
"It is about 20 yards from the back of the venue where the darts are held."
The victim, who has not yet been named, was rushed to Frimley Park Hospital but was pronounced dead on arrival.
Lakeside Professional World Darts Championships spokesman Robert Holmes confirmed the man was a fan enjoying the world famous tournament and added: "It is tragic and the weather played a big part.
"He was a darts fan but that's all I know - I have no details of name age or anything."
The man had been watching the televised second round matches — four of which were played yesterday evening.
During the evening, Martin Phillips beat Paul Carter 4-2, Martin Adams beat Daryl Gurney 4-1, Garry Thompson beat Martin McCloskey 4-1 and Scott Waites beat John Henderson 4-1.
A spokesman for Surrey Police said an investigation into the tragedy was under way.
He added: "Surrey Police can confirm that the body of a man has been recovered from the lake at Lakeside Country Club, Frimley Green after we were alerted to the discovery at about 10.45am Thursday."
Mark Webster | 10-8 | Raymond van Barneveld |
| 25 | 100+ | 26 |
| 11 | 140+ | 10 |
| 2 | 180s | 3 |
| 31.30 | Ave 1 | 29.98 |
| 93.90 | Ave 3 | 89.93 |
| 72 | High Finish | 118,113 |
| 5 | Legs Against Throw |
| Phil Taylor | 7-3 | Simon Whitlock |
| 57 | 100+ | 52 |
| 43 | 140+ | 32 |
| 9 | 180s | 11 |
| 34.79 | Ave 1 | 33.50 |
| 104.38 | Ave 3 | 100.51 |
| 170,167,161,131,122 | High Finish | 170,122,108 |
| 12 | Legs Against Throw | 7 |
