The defenders had been promised time. Operation Matador, a preemptive strike into Thailand, was supposed to keep the Japanese far from Jitra. When it was cancelled, three smaller delaying forces were improvised instead. The most exposed was Laycol, a column of two hundred soldiers from the 1/8th Punjab Regiment under Major Eric Robert Andrews, supported by a pair of 2-pounder anti-tank guns. Laycol pushed ten miles across the Thai border to Ban Sadao and had just finished digging in at 9 p.m. on December 9 when headlights appeared on the road. The vanguard of the Japanese 5th Division, some five hundred men of the reconnaissance regiment and 1st Tank Regiment under Lieutenant Colonel Saeki, was advancing with an audacity that bordered on recklessness. The small British force was quickly overwhelmed, and the road to Jitra lay open.

Murray-Lyon threw what he could into the path of the Japanese advance. Brigadier Garrett took the 1/14th Punjabs forward to Changlun, six miles from the Thai border, while the 2/1st Gurkha Rifles dug in at the village of Asun, just north of Jitra. The Punjabs were flanked in daylight and shattered. Lieutenant Colonel James Fitzpatrick, trying to improvise a roadblock with the survivors, was severely wounded when Japanese tanks rolled over his position. Garrett gathered roughly 270 survivors and escaped south. By evening on December 11, Saeki's column had reached the Gurkhas at Asun, where Lieutenant Colonel Jack Fulton's men waited behind a fast-flowing stream with demolition charges on the bridge but no anti-tank guns. Murray-Lyon had now lost the better part of three battalions before the main battle had even begun.

The main line at Jitra was held by the 1st Leicestershire Regiment and the 2/9th Jat Regiment, with Gurkha battalions covering the rear. When Saeki's advance guard overran a Leicester patrol at 8:30 p.m. on December 11, an improvised roadblock held them until dawn. Saeki, still believing he faced only scattered delaying forces, launched a three-hour assault on the main positions and was repulsed. By midday on December 12, he realized he had run into the full 11th Indian Division. General Kawamura committed the 11th and 41st Infantry Regiments for a night attack. The Jats' D Company, out of ammunition, was overrun. Communications broke down further as commanders lost contact with forward units. Murray-Lyon asked permission to withdraw thirty miles south to a natural stronghold at Gurun. General Arthur Percival refused, fearing the demoralizing effect of such an early retreat. Murray-Lyon was told the battle must be fought out at Jitra. By 10 p.m., with his line collapsing, the order to withdraw finally came.

After fifteen hours of fighting, the Japanese 5th Division held Jitra and a large stockpile of captured Allied supplies. The 11th Indian Division had lost a brigade commander wounded, a battalion commander killed, another captured, and the equivalent of nearly three full battalions of infantry. The division that stumbled south was in no condition to face another assault without reinforcements and rest it would not receive. Around the same time, Japanese naval aircraft struck Penang, killing more than two thousand civilians. Percival ordered all remaining Allied aircraft in Malaya withdrawn to Singapore. Murray-Lyon was relieved of command on December 23. The battle at Jitra was only the beginning. It established the pattern that would repeat itself down the length of the Malay Peninsula over the next two months: Japanese forces moving faster than anyone thought possible, outflanking positions that had been considered defensible, and exploiting the gaps left by incomplete preparation and broken communications.

Today the Jitra area is the administrative heart of the Kubang Pasu district in Kedah state, a landscape of rice paddies and rubber plantations that gives little outward sign of the violence that swept through in December 1941. The trunk road that carried Saeki's tanks still runs north toward the Thai border. The villages of Changlun and Asun remain, quiet stops along a route that was once the axis of a rout. The battle is remembered more in military histories than on the ground, yet it marked a turning point in the war for Southeast Asia. In those chaotic days, the soldiers of the 11th Indian Division, many of them thousands of miles from their homes in Punjab, Leicestershire, and Nepal, fought with what they had in positions they knew were inadequate. Their story is one of institutional failure more than personal courage, though they had courage enough.