[4] The PAVN moved into a series of pre-built mutually supporting bunkers surrounded by barbed wire which had been built over the preceding weeks unnoticed by the ARVN who were responsible for security in the area.

[2]: 294–5  The Marines called in air and artillery strikes which were reported to have knocked out three PAVN machine guns and Company H crossed the stream 400m northwest of Dong Xuan.

At 16:25 Company B 1/3 Marines aboard AMTRACs landed south of An Loc under cover of Task Force Clearwater gun boats.

[2]: 294–7 The 2/4 Marines commander Lieutenant colonel William Weise felt that inadequate resources were provided for the attack on Dai Do, both in terms of men and air and artillery support.

With limited Marine reserves available, Tompkins requested Army reinforcements from I Field Force commander Lieutenant general William B. Rosson who sent the 3rd Battalion, 21st Infantry Regiment to a landing zone north of Đông Hà on the morning of 1 May.

Outside the hamlet they saw a group of approximately 60 PAVN moving across paddyfields north of An Loc and opened fire on them in what was described as a "turkey shoot".

Company G was met by intense fire from the entrenched PAVN and had to knock out each bunker one by one, eventually reaching the north of Dai Do by 14:00 after having suffered heavy losses and both tanks being immobilized.

Meanwhile, Company G attacked PAVN positions in southern Dai Dao knocking out bunkers with White Phosphrous grenades, Satchel charges and M72 LAWs.

Hull liaised with the ARVN mechanized battalion which was now west of Dai Do and it was agreed that they would advance 1 km north to Thong Nghia while the Marines renewed their attack on Dinh To.

[2]: 303–4 The PAVN have never released their casualties for Dai Do, but claimed victory stating that they had defeated three Marine Battalions and elements of the non-existent US 73rd Air Cavalry Brigade on 2 May, killing over 500 Americans.

[5]: 508–9 Max Hastings writing in 2018, described Dai Do as an "act of sustained folly," blaming Hull and Tompkins for not appreciating the tactical situation and continuing with costly frontal attacks on 1 and 2 May.