UPDATED: If election night is half as close and contested as Thursday's ratings race, we're in for a heckuva evening.

John McCain's speech was watched by more viewers than Barack Obama's, according to Nielsen Media Research.

The Republican nominee beat Obama's record-setting convention speech viewership by 500,000 among broadcast and cable networks.

McCain's address at the Republican National Convention was seen by about 38.9 million viewers. Obama received 38.4 million.

That means McCain's speech is now the most-watched in convention history -- 41% higher than President Bush's acceptance speech four years ago, and 1% higher than Obama's address last week.

But wait.

If you add in PBS -- which is tracked by Nielsen as meter-market projections, but not counted among its regular national ratings sample -- Obama beat McCain.

PBS estimated that 2.7 million viewers tuned in last night and 3.5 million watched Obama. So if you include those viewers, Obama beat out McCain by an even slimmer margin, 41.9 to 41.6 million viewers.

Either way, a squeaker.

The usual practice is to use the numbers Nielsen announced. That's the official count, since a different measurement system is used for PBS, which unlike the others is not an ad-supported network. One could also try including viewers watching C-SPAN (which isn't tracked by Nielsen) or even online viewing. Given the amount of media attention that convention coverage ratings have received over the past couple weeks, with the whole Nielsen race becoming a sort of pre-election election, there's always a few more ballots to be found somewhere.

The bottom-line point to extract from all these numbers is that last week few would have predicted that McCain would draw an audience that compared to Obama's. Attendance of their live appearances have been pretty unequal. By any viewership measurement, McCain managed to roughly match his opponent last night, indicating that interest in the candidates may not be as disproportionate as some have assumed.