The Reds' striker scored the first goal to ease some of the nerves around Wembley early in the second half, and it had United stamped all over it.
Danny Welbeck saw his shot saved by Montenegro keeper Vukasin Poleksic, but his Reds team-mate was on hand to sweep England into the lead, bagging his 37th international goal in the process.
The second goal also had an Old Trafford influence, with Welbeck's pull-back from the left played into his own net by Branko Boskovic.
The visitors quickly reduced the arrears, but Andros Townsend's debut goal and Danny Sturridge's late penalty saw England through to a result that means a win over Poland on Tuesday will be enough to qualify for Brazil. Michael Carrick also featured, playing for the last 25 minutes
Marouane Fellaini helped Belgium guarantee their passage to next summer's finals with a 2-1 win over Croatia. The United midfielder, playing with his injured wrist in a cast, was booked after an hour but by then the highly-rated Belgians were already two goals up through two first-half strikes from Romelu Lukaku. Niko Kranjcar pulled one back, but it wasn't enough to deny Marc Wilmots' side.
Robin van Persie entered the record books for the Netherlands, his hat trick against Hungary making the 30-year-old his country's greatest international goal scorer. His third, part of an 8-1 thrashing, was his 41st in international football and saw him overtake Patrick Kluivert.
But it was a night to forget for Jonny Evans in Baku, the United defender was sent off late in Northern Ireland's 2-0 defeat to Azerbaijan. Nani played in Portugal's 1-1 with Israel, which means that