The 36-year-old former world No 2 announced at the start of this month that the showpiece tournament at the University of Hull would be her last after 20 years on the world tour.
It took only 20 minutes for tournament favourite El Welily to win 11-2, 11-6, 11-4 against Duncalf, who afterwards said she was leaving the sport in good hands.
“Raneem is a fantastic player and person off court and for all the kids watching any person to look up to as a player or human being then I would suggest following her,” said Duncalf, who underwent a hip operation at the start of the season.
“Getting to world No 2 was great and having a couple of big wins at tournaments to get there. I’d have loved to have had a better last few years or maybe to have won a major, but absolutely no regrets.
“I was sort of borderline retiring before the Commonwealth Games last April. I needed a hip operation and I thought I would see how I got on, but it’s a struggle playing all these youngsters and I’m so pleased to be leaving the sport in good stead.”
El Welily will now face the USA's Amanda Sobhy in round three after she defeated Canada’s Samantha Cornett on the side courts, but was quick to pay a post-match tribute to two-time British Natioanls winner Duncalf.
“Jenny is one of the most skilled English players that I have ever seen play the game,” said 30-year-old El Welily.
“I’ve enjoyed watching her and I wish her all the best. I hope Jenny will enjoy her moment though and we will certainly miss her on tour. She is such a good player on court and a great person off court."
Tuesday also saw two other leading lights of the women's game head off into the distance as defeats for former winners Nicol David and Laura Massaro signalled their respective retirements.
Malaysia's David, who won five British Open titles and spent an unprecedented nine years at world No 1, bowed out 11-4, 11-7, 11-13, 11-5 to world No 3 Nour El Tayeb, bringing an end to her 21-year career on the PSA World Tour.
Two-time winner Massaro saw her career come to an end at the hands of Belgium’s world No 39 Tinne Gilis in a surprise 11-5, 2-11, 11-5, 11-7 defeat.
Elsewhere, in the men's draw, three-time runner-up James Willstrop, from Pontefract, saw his hopes of reaching the third round ended by No 2 seed Mohamed ElShorbagy, who won a tight contest 11-9, 11-9, 11-9 in 40 minutes.