In a full day and night of fierce fighting on August 25, the 1st Battalion, 2nd Infantry; 1st Battalion, 26th Infantry; 1st Battalion, 16th Infantry; and A and C Troop, 1st Squadron, 4th Cavalry engaged the famed VC main-force Phu Loi Battalion, killing 171 and capturing six in thick jungle base-camp areas approximately four mile east of Lai Khe and 25 miles noth of Saigon of Highway 16. The VC casualties amounted to 50% of their battalion destroyed.
A 15 man ambush patrol set out the day before from Company C, and the Recon Platoon, 1st Battalion, 2nd Infantry radioed for help at 7:40am, after encountering an estimated battalion in what later proved to be heavily fortified base camps. Helicopter fire teams reacted immediately to the call for help and started firing on the enemy within ten minutes. C Troop 1st Squadron, 4th Cavalry and the remainder of C Company, 1st Battalion, 2nd Infantry rushed to assist.
Diverted from a Highway 16 clearing mission, the 1st Battalion, 26th Infantry and B Troop, 1st Squadron, 4th Cavalry also joined the fight, encountering heavy resistance in a series of bunkers and machine gun positions. As the fight intensified, the 1st Battalion, 16th Infantry was air lifted was air lifted fro Lai Khe and began an attack eastward, locating another base camp and encountering M79 grenade-launcher fire and claymore mines.
By 8:30am VC resistance had diminished considerably. Air and Artillery pounded likely avenues of escape. The infantry battalions linked up in search and clear operations. Demolition teams from the 1st Engineer Battalion began destroying the large and sophisticated tunnel and cement-bunker complex.
The results of the search operations proved the enemy was not only well dug-in but also well equipped. Found were three 60mm mortars, three rifles, one Browning automatic rifle, one pistol, three radios, miscelaneous medical supplies, pioneer tools, gas masks and uniforms. Later destroyed were 82 60mm mortar rounds, an assortment of claymore, anti- personnel and anti-tank mines, TNT, hand grenades, small-arms ammunition and one radio. Company C, 2d Battalion, 28th Infantry discovered and destroyed 600 pounds of rice. Division casualties were described as moderate to heavy in four companies. The other eight companies had light casualties.