Sensex on Thursday fell over 133 points to close at a one-week low of 28,666.04 while NIFTY dropped by 43.50 points to 8,706.70. Tata Consultancy's quarterly results were expected later in the day, leading to selling pressure on other IT stocks which ended up as the day's top 3 losers. The Sensex has now lost 378.4 points in two days.