The Minnesota Vikings and Pittsburgh Steelers served up a special game on the Wembley turf on Sunday night, and the sight of an 84,000-strong crowd savouring every minute is becoming almost routine in London - which is just how the NFL wants it.

Minnesota won 34-27, holding off a last-minute Pittsburgh drive, in the seventh NFL game played in North London in as many years. The novelty value is gone but, with the next Wembley game only a month away and also heading for a sell-out, it is clear these games have staying power, lending optimism to those who believe a London-based franchise will be viable in the near future.

This season is the first in which the NFL will stage multiple games at Wembley, with the late October tie between the Jacksonville Jaguars and San Francisco 49ers the first of four games Jacksonville have committed to play in the capital over the coming years. Such is the ongoing success of the league's London project that NFL UK finds itself in the unusual position of being the ones trying to rein in expectations rather than promote their own achievements.

"It's exciting to see people getting behind the thing but I think I've become the anti-promoter," said managing director Alistair Kirkwood. "I have to keep saying 'hold on' to people. So much goes into each of these events that they can't be seen as a given. We want to build it with a level of credibility.

"It's all about the sport, and we want to make sure that everything we do and say is backed up. Too many times in sport there is a lot of hyperbole and speculation and then people feel a little bit cheated."

This was arguably the best yet in the International Series. The close game was the most engaging since the New Orleans Saints edged the San Diego Chargers 37-32 back in 2008, while the weekend as a whole - starting with a huge party on Regent Street on Saturday which attracted hundreds of thousands of people - made a major impact.

NFL UK has no time to rest on its laurels, however, with the days counting down to the next game already. The commitment made by the Jaguars - owned by Fulham owner Shahid Khan - is unlike any other in the short history of these London games, with the hope that unattached British fans will be able to identify with a team which returns to these shores several times.

"This will really be the start of a Jacksonville journey," Kirkwood said. "We're going to get more familiar with the team as they keep coming back so we can all be part of their progression as a team."