Mr Pillay told the New Zealand Herald that he could have been knocked unconscious if it were not for a passenger grabbing his attacker and pulling him aside.
The attacker ran off before police arrived and they are asking for public help to identify him.
"This was a pointless attack and one that came suddenly and without warning," said the NZ Bus spokeswoman.
"Our focus as a business is making sure that Logan is alright and recovering.
"We will be formally investigating the incident to see if there are any learning to help avoid a similar incident in the future."
"Attacks of this nature, which are sudden and unprovoked are not common and for that reason difficult to plan for.
"In some instances, passengers that have been identified as confrontational will be trespassed from our services, but that is not a failsafe solution.
"Our drivers all have radios with panic buttons that can be initiated where they feel threatened.
"In this case Logan did not have any prior knowledge that something would transpire and for that reason no call was lodged."
However, Auckland Tramways Union president Gary Froggatt stood by his estimate of one assault a week out of 1100 NZ Bus drivers.
"The seven quoted by AT would be the serious ones that get reported.
"Many go unreported by drivers - it's not an epidemic of assaults but it's still cause for concern."
Mr Froggatt said there were strict protocols for handling aggressive passengers and he would be talking to NZ Bus health and safety management about greater enforcement of them.
This was especially needed now, with a crackdown on fare evasion and ruses such as passengers offering photo copies of SuperGold cards to get a free ride.
"They get aggressive when challenged by the driver."
Regarding Auckland passenger safety, Mr Hannan of AT said it was uncommon to have passengers fighting on trains and buses, or at stations.
The new electric trains had the added presence of Pacific Wardens and 18 CCTV cameras in carriages.
Stations for trains and buses had 20 to 30 CCTV cameras which were monitored by AT security staff.
NZ Bus Auckland - Assaults on Drivers
March 21- 6pm, at Manukau
April 9 - 8.35am, Manukau
June 5 - (time not available), Newmarket
June 6 - 3.50pm, City
June 6 - 8.50pm, Browns Bay
August 4- 3.55pm, City
August 5 - 5.57pm, Blockhouse Bay
(Source: Auckland Transport)