THE Mets blew the big game on Sunday – but gained a historic TV audience in the process.

Sunday’s Mets-Marlins matchup, the last-ever game at Shea Stadium, averaged nearly 822,000 viewers on SNY – the highest-rated game in Mets history on a regional sports network.

The game, in which the Marlins knocked the Mets out of playoff contention, peaked with 1.3 million viewers.

For the 2008 season, SNY posted the best ratings of either New York baseball team in adults 25-54 and men 25-54.