Sa was left to command remaining Burmese troops in Arakan after Bandula and the main battalions were ordered to withdraw from Arakan by Bagyidaw to meet the British invasion in Yangon in August 1824. Sa held on to Arakan throughout 1824 when the main focal point of the war played out in Yangon. After Gen. Archibald Campbell finally defeated Gen. Bandula in the Battle of Yangon in December 1824, the British turned their sights to Arakan. On 1 February 1825, an invasion force of 11,000 soldiers supported by a flotilla of gun boats and armed cruisers along the coast and a squadron of cavalry under the command of Gen. Morrison attacked Burmese positions in Arakan. Despite their superior numbers and firearms, the British had to fight Sa's depleted Burmese forces for nearly two months before they reached to the main Burmese garrison at Mrauk-U, Arakan's capital. On 29 March 1825, the British launched their attack on Mrauk-U. (At the same time, Campbell also launched an attack on Bandula's positions in the Battle of Danubyu.) After a few days of fighting, the Burmese at Mrauk-U were defeated on April 1, coincidentally the same day Maha Bandula fell at Danubyu. Sa and remaining Burmese forces evacuated and left Arakan. The British proceeded to occupy the rest of Arakan. Sa saw firsthand the destructive power and discipline of the British army.