Lampard has helped Luiz Felipe Scolari's side set the early pace this term, opening up an eight-point gap on the Red Devils along the way though United to have a game in hand on the Blues.
That advantage was helped by United's 2-1 defeat at Arsenal Saturday, while Chelsea made light work of Blackburn at Ewood Park 24 hours later.
The Emirates setback was United's second loss of the season, while Chelsea have lost just once in the Premier League.
And with that in mind, Lampard believes the Blues' fellow contenders for the crown can't afford anymore slip-ups.
"It's a nice gap for us," the England international told the Evening Standard.
"It is far from over, but in the last two years it's been the other way around. We've been five points behind and it is not easy. When you are chasing, you really can't afford to lose games.
"You have to remember Liverpool are neck and neck with us. But Man United and Arsenal, who are always big contenders, are those few points behind."
Chelsea came desperately close to taking the title last season, eventually ending the campaign just two points adrift.
Their failure to keep pace with United at the top ultimately proved costly and Lampard is determined to avoid a similar occurrence this time around.
"It is not easy to chase, the pressure builds up and if you drop points you fall further behind," he added.
"It's difficult either way, because the big four don't lose too many games or drop too many points.
"You certainly don't want to be too far behind at this point.
"We did it last year and we made a lot of ground up. However, in the end we lost the title by two points, so it feels nice to be in the lead at the moment."