The day's turnover hit its highest in seven months, boosted by block deals in Lanka Ceramic PLC.
The main stock index rose 1.8 percent, or 107.99 points, to 6,121.17, its highest close since Dec. 1, 2011.
Shares have been rising on expectations of a fall in interest rates after Treasury Secretary P.B. Jayasundera and the central bank said interest rates could ease in May-June.
The International Monetary Fund said on Thursday Sri Lanka must not loosen monetary conditions as inflation remains a concern, even though prices had risen at a slower pace in April than the previous month.
The market has gained 5.95 percent since the treasury secretary's comments on April 9.
'Retail and high networth investors pushed the market on hopes of falling interest rates,' said an analyst.
Shares in market heavyweight John Keells Holdings rose 2.93 percent to 260.20 rupees a share.
Shares in Lanka Ceramic PLC, which pushed the day's turnover on a block deal, jumped 50 percent to 120 rupees a share.
Royal Ceramics Lanka PLC, which rose 3.40 percent to 100.50 rupees a share, said in a filing with the bourse it bought 22.83 million shares of Lanka Ceramic in a price range of 86.90 rupees to 120 rupees.
The turnover was 4.14 billion rupees ($32.79 million), well above this year's daily average of 963.9 million rupees, and the highest since Sept. 16, 2012.
Foreign investors were net buyers of 28.22 million rupees of shares, extending the net foreign inflow so far this year to 8.96 billion rupees. Last year, the bourse saw a net inflow of $303 million.
The rupee ended at 126.40/50 per dollar, weaker from Friday's close of 126.30/40, on importer dollar demand, said currency dealers.
($1 = 126.2500 Sri Lanka rupees)
(Reporting by Ranga Sirilal and Shihar Aneez; Editing by Prateek Chatterjee)
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