This time the PAVN succeeding in penetrating the perimeter before again being forced back by defensive fire, air and artillery strikes.

Eventually on 13 May with intensive air support the 31st Regiment overran the PAVN positions and extended ARVN control to 8 km north of Chơn Thành.

On 15 May 1972 an ARVN task force of the 15th Regiment, 9th Division which was redeployed from the Mekong Delta and the 9th Armored Cavalry Squadron moved north east of Route 13 bypassing the 209th Regiment's roadblock at Tau O to establish a fire support base at Tan Khai 10 km south of An Lộc.

The battle was a turning point in the war because it showed that the United States was no longer prepared to intervene militarily to save South Vietnam and that the ARVN was overstretched with limited ability to respond forcefully to PAVN offensive action.

The ARVN 18th Division withstood the initial attacks and on 12 April were reinforced by men of the elite 1st Airborne Brigade and Vietnamese Marines.

[9]: 129–34  The 4th Corps pushed on towards Biên Hòa and at 5pm on 26 April they attacked Bien Hoa Air Base and Long Binh Post.

[9]: 154  By the morning of April 28 troops from the 4th Corps overran ARVN positions at the eastern end of the Newport Bridge.