A hospital spokesperson said a man, aged in his 20s, was transferred to Wellington Hospital in a critical condition for further treatment on Saturday afternoon.
SH2 was blocked on Friday night with one lane able to be used by 8am Saturday and it fully reopened at 10am.
Two people were also critically injured in a single-vehicle crash in Hawke's Bay just before dawn on Saturday, police confirmed.
Police were called to Ormond Rd in Twyford, on the outskirts of Hastings, at 7.20am.
The crash was believed to have occurred about 3.40am.
The Holden vehicle appeared to have failed to take a bend and hit a tree.
Two men were taken to Hawke's Bay Hospital by ambulance with critical injuries.
A hospital spokesperson said they were still in a critical condition in the intensive care unit yesterday.
Ormond Rd was closed near the intersection with Evenden Rd and reopened about 11.40am on Saturday.
The serious crash unit also attended.
At least seven other crashes also occurred on Hawke's Bay roads at the weekend.
One occurred in the same place as the fatal crash at Nuhaka on Friday night.
Fire and Emergency said a car went off the road on SH2 at Nuhaka about 3pm on Saturday.
The vehicle's sole occupant was not injured.
Emergency services were also called to two crashes on SH5 near Tarawera and Te Pohue and another on SH2 near Takapau overnight on Friday and Saturday morning.
Police said one lane of SH5 was closed for a short time after a single-vehicle crash about 10.40pm on Friday near Turangakumu Rd.
The vehicle had rolled and landed on its side but no one was hurt.
One person was processed for excess breath alcohol and inquiries are ongoing, police said.
Two people were also uninjured after the vehicle they were in rolled down a bank on SH5, south of Te Pohue, about 6.30am on Saturday.
The occupants were out of the car and on the roadside when emergency services arrived.
Police are looking for a person who fled the scene of another single-vehicle crash after a car hit a power pole on SH2 near Takapau at 12.53am on Saturday.
Haumoana Volunteer Fire Brigade was called to a crash, which occurred between a car and a cow on Lawn Rd, Clive, at 11.55pm on Saturday.
Fire and Emergency said the sole occupant of the vehicle was uninjured but the cow had to be put down by a vet.
A car also hit a lamp post on Pakowhai Rd, Hastings, at 3.43am yesterday and the sole occupant was taken to Hawke's Bay Hospital by ambulance in a serious condition.
Emergency services were also called after a concrete power pole was knocked over, apparently by a vehicle, about 9am yesterday on St Aubyn St East but the vehicle was not on the scene, a Hastings Volunteer Fire Brigade spokesperson said.
