Currently ranked at number 40 in the world, Raducanu regained her position as British number one at Queen's earlier this month.
Generally looking happier and more relaxed, the 2021 US Open champion has reached two WTA quarter-finals this year and returned to the world's top 40.
But, after a difficult build-up which included an emotional tournament at Eastbourne last week and having to pull out of the Berlin Open because of an ongoing back issue, Raducanu said she "does not expect much" at Wimbledon.
But she quickly looked at home in front of a home crowd eager to support both sides with cries of "come on Britain!" from the stands.
An immediate break of serve gave Raducanu a foothold in the match and more break points followed.
But Xu, who is ranked just outside the top 300 in the world, fended them off in a lengthy third game, much to the delight of the Welsh fans in attendance, willing on their first player to enter the Wimbledon main singles draw in 20 years.
Xu held her own and settled into the match but a slew of mistakes eventually handed Raducanu the first set.
The second set began in much the same fashion, with an early break of serve from Raducanu.
But this time Xu responded with a break of her own and a topsy-turvy encounter followed as neither player could hold onto their serve.
Raducanu eventually held at 5-2 and that laid the foundations for her to book her place in the second round for the fourth time in her career.