Kiatisuk Senamuang's side were beaten 3-0 by China last Friday but recovered well to extend New Zealand's winless run to nine matches.
Goals in either half from Kirati Keawsombat and Adisak Kraisorn wrapped up the friendly win at the 80th Birthday Stadium to provide Thailand a boost ahead of their Championship opener against Singapore on Sunday.
The visitors had gone closest to breaking the deadlock early on, as they threatened Kawin Thamsatchanan's goal with efforts from Bill Tuiloma and Marco Rojas inside the opening 20 minutes.
Rojas was replaced by Tim Payne after half an hour but New Zealand's pressure continued as Marseille man Tuiloma fired over the bar from distance.
However, Thailand responded and saw an effort hit the crossbar before Keawsombat opened the scoring a minute from the break.
After the ball was cut back into the area, the PTT Rayong striker drove home from inside the area to give the hosts a half-time lead.
While Anthony Hudson's side huffed and puffed in the second half, they were unable to regain a foothold in the match.
Chris Wood and Jeremy Brockie were the main threats, with Hudson handing a debut to Kayne Vincent as the visitors sought to end a run of eight games without a win.
However, when Jacob Gleeson parried a long-range effort, Kraisorn snaffled up the rebound to wrap up the win - bolstering Thailand ahead of their Group A opener against the defending champions in Singapore at the weekend.
