Hanna Oeberg stormed back from almost a minute down to take silver for Sweden, 10.7 seconds behind Domracheva, and Anais Bescond claimed bronze for France.
Domracheva celebrated her fourth Olympic gold medal with her husband, Norwegian biathlon great Ole Einar Bjoerndalen, who has eight Olympic golds to his name but was not selected for Pyeongchang.
"It was big celebration, big happiness, he was surprised and felt the same as we did," she told reporters.
"Such medals mean it's important to believe in yourself, important to believe in your team, to overcome some difficulties, then all doors are open for you," she added.
The weather conditions made for a tough, tight race during which the lead change hands on virtually every visit to the range as the biathletes struggled to judge the wind.
Italy, Poland, France and Slovakia all headed the pack at some point but it wasn't until Domracheva, who won a silver medal in the mass start, took over on the final leg that the field started to stretch out.
Her powerful skiing allowed her to build a lead and even survive what could have been costly misses on the final shoot before surging to victory.
The 31-year-olf found time to grab a Belarusian flag but it flew off before the finish line and she was left to cross it only carrying the pole.
Sweden's Oeberg looked to have an impossible task at the final exchange, almost a minute down, but the 22-year-old individual gold medallist tore through the field to take the silver.
Her superb finish prompted a huge outpouring of joy at the finish line as coach Wolfgang Pichler threw an arm around the shoulders of Sweden's King Carl Gustav.
"They have fought incredibly well, it was very hard conditions today. It's the same for everyone of course, but they did it really well in the last leg. Really, really well," the king told reporters.
Oeberg was delighted at the prospect of sharing an Olympic podium with her team mates when their medals are presented on Friday.
"This team has worked together really hard for the last couple of years, that we're here to day is unbelievable," she said.
"I'm really happy to share this medal with the girls, it means so much to me."
(Reporting by Philip O'Connor, editing by Ed Osmond)
