* Turkish lira sole EMEA gainer on inflation optimism * Polish zloty at near one-month low * EM stocks see extended profit-taking Jan 28 (Reuters) - The Russian rouble led losses across emerging market currencies on Thursday as geopolitical tensions weighed, while stocks were set for their worst day in nearly two months, tracking a weak performance on the Wall Street. The rouble sank 1% to its lowest level since early-December, as concerns over western sanctions grew after the arrest of Kremlin critic Alexei Navalny and subsequent protests sparked criticism from U.S. officials. Weakness in the crude market also weighed on the rouble, which breached a key 76 to-the-dollar level.