Gold posted its biggest-ever single day gain of 1,310 rupees, to hit yet another all-time high of 28,150 rupees per ten grams at Delhi's bullion market on Saturday following frantic buying triggered by strong demand in the global markets. Silver surged 1,500 rupees, to 62,800 rupees per kilo.In London, gold climbed to a fresh record high of 1,868 dollars an ounce, as melting global equity markets, poor US economic data, and growing concerns over Europe's sovereign debt crisis prompted investors to seek the perceived safety of bullion.