Mayor Michael Bloomberg is starting off this election year in the lead, but it's not as wide of a margin as one might expect for the popular incumbent.

According to an exclusive NY1 poll, Bloomberg beats City Comptroller Bill Thompson by 13 points in a hypothetical matchup, but only wins reelection against Congressman Anthony Weiner by seven points.

It's a sign the mayor will have to wage an aggressive campaign.

"He does have his work cut out for him because he is not at the comfortable 50 percent," said NY1 pollster Mickey Blum.

That may come as a surprise because the mayor's approval rating is still quite high, now at 64 percent.

Bloomberg is beloved among all demographic groups. For instance, his approval rating among black voters is nearly 61 percent.

But when he's paired up against either Weiner or Thompson, his support among black voters cools, as well as among other groups.

Weiner beats the mayor among young voters, those making between $30,000 and $50,000 a year, black voters and essentially ties the mayor among Latinos -- a group Bloomberg has been targeting for years.

At this point, Weiner has an approval rating of 42 percent. Thompson's approval rating is higher, at 48 percent.

Weiner, who came close to beating Fernando Ferrer in the 2005 Democratic primary, beats Thompson in the upcoming primary. The numbers show Weiner getting 31 percent, Thompson receiving 22 percent and Queens City Councilman Tony Avella running a distant third.

"That contest is anybody's because at this point 'not sure' is winning," said Blum.

Then again, it's incredibly early. Once they start campaigning, and Mayor Bloomberg starts blanketing the airwaves with commercials, the numbers could start to look drastically different.