[1]: 32, 37 The Moros accused the Americans of trying to convert them from Islam to Christianity, just like the Spanish attempts, and held a grudge from 1900 when troops under Lt. Col. L. M. Brett killed Datu Amirul.

Once they finally reached the 2 forts at Bayang and Pandapatan, the number of effective guns had dropped to 600 and they had lost their Maguindanao cargadores and replaced them with an additional 40 pack mules, 80 in total.

Fifteen minutes after the ultimatum expired at noon, Baldwin's men—Company F (1st Lt. Thomas Vicars) and Company H (Captain Samuel Lyon)[3] — started their attack of the Moro fort on Lempesses Hill.

When the Americans commenced their assault, they managed to take out a number of defenders on the walls of the fort, but lacking scaling ladders and running low on ammunition, Hugh A.

On the way back to camp near the ruins of the Binidayan cotta, flashes of lightning, accompanied by heavy fog and a deluge of rain made life miserable for the Americans.

[1]: 36  As the Americans withdrew to Binidayan, the 25th Field Artillery courageously crawled on to the battlefield and retrieved the dead and wounded, although they were beaten back and suffering from heavy rain and fog, they inflicted massive damage to the fort and to the morale of the Moros defending it.

This first battle at Bayang became the rallying call of the Moros across Mindanao, with the continuing presence of American troops sparking various uprisings and attacks across the islands of Sulu, the Lanao lake and the Cotabato Basin.

Behind the scenes President Roosevelt was furious with General Chaffee for having apparently allowed an entirely new front to open up just as he was about to proclaim the Philippine Islands were finally pacified and peaceful after a grinding, 3+1⁄2-year-long, less than popular war.

In addition it undercut a slower yet progressively more successful attempt initiated by Davis to negotiate a peaceful solution through the efforts of Captain John J. Pershing.

In fact Chaffee believed that had it not been for Pershing's last minute success in convincing the most powerful datus at the north end of the lake not to join in the defense of Bayang, Baldwin's expedition might have been a disaster.

The battle locally known as the Padang Karbala by the Maranaos is regarded as an instance of Moro resistance against imperialism and colonization of the United States and as a proof of ethnic nationalism.