The second battle of Tiruvadi (1 September 1750) saw a French led army defeat a much larger force commanded by Mohammad Ali, the British-supported candidate for the Nawabship of the Carnatic (Second Carnatic War).
During 1750 the British-supported candidate, Nasir Jang, was Nizam of Hyderabad, while the French-supported candidate, Chanda Sahib, was Nawab of the Carnatic. Early in the summer Nasir Jang advanced towards Pondicherry, but was discouraged by a night-time attack on his camp and retired to Arcot. His British allies retreated to Fort St. David, leaving only Mohammad Ali in the field. He took up a position near to Tiruvadi. The French responded by occupying the Pagoda at Tiruvadi, an easily fortified stone building that gave them a foothold across the Panar River, threatening the British position. Nasir Jang and the British both sent troops to aid Mohammad Ali, but an assault on the French position failed (first battle of Tiruvadi, 30 July 1750). The British soon argued with Mohammad Ali, and returned once again to Fort St. David.
Mohammad Ali took up a poorly chosen position on the Panar River, between Tiruvadi and Fort St. David, and with the river to his back. His mainly cavalry army was still 20,000 strong, but his position was weak.
Joseph Dupleix, the French governor of Pondicherry, realised this, and sent reinforcements to d'Auteuil. His original 500 men were joined by 1,200-1,300 European troops, 2,500 Sepoys and 1,000 cavalry led by Chanda Sahib. This gave d'Auteuil 5,200 men.
The French attacked Mohammad Ali in his camp on the afternoon of 1 September. They advanced with the artillery in front, the infantry behind and the cavalry on the wings. As the French advanced they stopped to fire occasional volleys from their artillery, and Mohammad Ali's gunners responded with their own fire.
When the French and their allies were 200 yards from Mohammad Ali's camp, d'Auteuil ordered his infantry to charge. Mohammad Ali's men didn't attempt to defend their fortifications, and instead fled towards the river. The French quickly captured the entrance to the camp, brought up their guns, and fired on the mass of enemy troops attempting to cross the Panar. Fortunately for them, the river was fordable, and most of the army was able to escape, but only after around 1,000 were killed. French losses were negligible.
In the aftermath of this defeat Mohammad Ali fled towards safety at Arcot, while most of his troops retreated to the strong fortress at Gingee. This was widely believed to be impregnable, but the French captured it in a single day (battle of Gingee, 11 September 1750), making themselves masters of the Carnatic.