Mesopotamia – Battle of Kut: after night flank march, Townshend (1,233 casualties) storms Turk defences (700 casualties) at Es Sinn, taking 1,153 PoWs and 14 guns. Nureddin makes orderly retreat towards Baghdad.
Loos: British Guards (2,000 casualties since September 27) capture chalk pit near Hill 70. French relieve hardpressed British line at Double Crassier-Loos. OHL orders XI Corps from Eastern Front as reinforcements.
Champagne: French penetrate German second line but on too narrow a front, V Cavalry Corps returns to St Remy as breakthrough not imminent.
Russian general Brusilov forced back until September 30 and abandons Lutsk to German troops under Linsingen. Hoffmann diary: ‘We want a good long rest for our tired divisions’.
Baltic: Russian submarine Bars with British boats E8 and E19 (first ship sunk on October 3) sail from Reval to attack German merchant shipping.