'It's fantastic to have won a main tour title, I'm delighted because I was playing under pressure and I came through it,' said Emerson. 'I was really pleased with the way I played the back nine.'
Markus Brier of Austria took second place at 14-under-par 274, while Welshman Kyron Sullivan followed at 13-under-par 275. Sweden's Mattias Eliasson was one shot further back at 12-under-par 276.
After heavy rain on Saturday forced the suspension of play, Emerson, along with many others, returned to Le Meridien Moscow Country Club to begin a marathon final day. Emerson took advantage and completed a third-round 68 that moved him into a tie for the lead with Germany's Kariem Baraka.
Emerson quickly got back to work and birdied the first two holes of his final round to move ahead at 14 under par. While Baraka struggled out of the gate, Emerson coasted on the front nine to hold the outright lead around the turn.
'Today, I just played really solid. I birdied the first and the second holes which was a great start and then things went a bit flat and I was leaving a lot of my putts short,' said the 40-year-old.
The Englishman stumbled to a bogey at the par-3 11th as Brier was putting on the pressure. Emerson recovered with a birdie at the par-4 14th and sealed the deal with back-to-back birdies starting at the par-3 16th.
'I've played on the tour for ten years and lost my card last season so I feel as though I have got my job back to be honest,' said Emerson. 'I have been playing the best golf of my career this year and to win on the European Tour, which is what we all want to try and achieve is fantastic.'
Brier, who shot a 69, collected five birdies and two bogeys for his best finish since he was the runner-up at the Open de Espana in 2000.
Henrik Nystrom, who shared the 36-hole lead with Baraka, carded a 2-under 70 in the final round to finish alone in fifth place at 11-under-par 277. Gregory Bourdy and Philip Archer shared sixth place at 10-under-par 278.
Nick Dougherty, Alessandro Tadini and Chris Gane tied for eighth at 9-under-par 279.
Baraka, the nephew of European Ryder Cup captain Bernhard Langer, opened with event with a blistering 63 on Thursday, but was unable to break 70 the rest of the way. Baraka closed with a 76 to finish in a group at 8-under-par 280.