The Sensex opened with a positive gap of 33 points at 12,547. The index slipped a bit to touch a low of 12,531, but soon shot back to zoom past the 12,600-mark.Steady buying, thereafter, saw the index rally to a new all-time intra-day high of 12,624. Intra-day profit booking saw the index slip towards the day's open and then bounce back to end with a gain of 99 points at 12,612.