The All Share Price Index closed up 0.10 percent (2.39 points) at 2,406.39 while the Milanka also ended firmer, up 0.31 percent (8.55 points) at 2,792.87.
Turnover was 491 million rupees.
Brokers said small investors, who had been inactive, waded in after seeing some institutional buying.
A slight easing of interest rates may have also helped.
High inflation and interest rates that erode company profitability had dampened investor enthusiasm for stocks and contributed to the market's slumber.
"There was quite a bit of retail activity today on low cap stocks and strategic buying on AMW," said Dihan Dedigama of Asia Securities.
"Also, there was strong buying in JKH, Colombo Dockyard and CIC."
But Dedigama said the overall market sentiment remained unchanged.
Associated Motorway closed flat at 174.50 rupees, the price at which Dubai's Al-Futtaim took control of the firm and made a mandatory offer for the remaining shares.
Just over a million shares AMW shares were traded with Al-believed to be continuing to buy into the stock.
John Keells Holdings ended up one rupee at 100 rupees with 668,800 shares changing hands.
Brokers said shareholders were selling the stock after its reputation got damaged when the supreme court ruled it had obtained illegal benefits in buying the Lanka Marine Services bunkering monopoly in a privatization exercise.
There was also speculative trading in 'small cap' stocks.
Colombo Fort Investments went up 37.50 percent or nine rupees to 33 rupees with 611,500 shares traded
Ceylon & Foreign Trades was up 6.63 percent or 2.75 rupees to 44.25 - 437,200 shares traded