BOSTON - Six months after the Massachusetts Lottery rolled out a $50 scratch ticket - its priciest scratch ticket ever - a winner has claimed the "Billion Dollar Extravaganza" game's first $25 million prize.

The actual winner was not named, but the one-time payment of $16,250,000 before taxes was claimed Tuesday by trustee Marco Schiavo of the Simmons & Schiavo Lottery Trust. Simmons & Schiavo is a Woburn-based law firm.

A Speedway at 709 McGrath Highway in Somerville sold the winning ticket. The winner plans to use the money to buy real estate and invest, Schiavo said.

There are still two $25 million prizes left in the game, five $2 million prizes and eight $1 million prizes still out there.

The Lottery says 12.6 million "Billion Dollar Extravaganza" tickets have been sold so far. Three million of those have been claimed as winners, paying out $485 million in prizes. The odds of winning a prize of at least $100 are 1 in 4.10.

Sales of the expensive game helped to turn around a scratch ticket slump in Massachusetts earlier this year.