She travelled non-stop from her previous competition in the United States to the town of Lazzate for the final round of the 2017 European Championships.
After first winning the European title back in 2013, Bristow took a three-year break from the series, but decided to compete again this year.
She topped the international field from runner-up Thersea Baumlm, from Germany, and Norwegian rider Ingveig Hakonsen who finished third.
Bristow said: “There is no better training than competition and my hunger to keep at the top of the women’s sport has pushed me to do everything I can this year to try and win my fourth World Championship.
“I saw the Europeans as perfect training and I took the series very seriously so I’m really happy to win this title.”
The trial, held in the north west of Italy, consisted of two laps of 14 sections, and in the blistering 38 degree heat, the dusty and hot conditions made for a physically tough day for many of the field.
Bristow opened a five-point lead over her nearest rival after the first lap, but going into the second lap she wanted to better her own performance .
The Lincolnshire rider did just that with a final lap score of only two points to give her a total of 14 to leave her 10 points clear at the top.
“On my second lap I found my rhythm and began to ride well and overall I am pleased with my performance to take a good win,” she said.
“I’m very happy to be European Champion again; the trials are very well supported and I love winning. It’s been a good season so far, but I hope there is more to come!”
Emma has a busy month ahead including both the men’s and women’s British Championship, and the prestigious Super Trial as well as more training for the close of the World Championships next month when the series moves to the Czech Republic and Italy.