By hitting the milestone at the Monte-Carlo Masters last weekend, Nadal became the first man in the Open era to win the same ATP Tour event 10 times.
There never looked any doubt that he would repeat the feat in Barcelona on the court that bears his name, and he duly romped to a 6-4 6-1 victory over Dominic Thiem in the final.
Nadal will go for a 10th title at the French Open in a month's time, and on this form he unquestionably heads to Roland Garros as the favourite.
Thiem defeated world number one Andy Murray in the semi-finals and stayed with Nadal over the first eight games.
But the third seed claimed the first break of serve to win the opening set and did not look back, repelling all Thiem's firepower in the second set and forcing the Austrian to overhit.
Nadal, who first won the title in 2005, said: "I'm very satisfied. It's been an emotional day for me. Playing in front of my crowd and my club and winning a 10th title here is something that's impossible to even dream of. It's very special and unique.
"I played my best match of the tournament this afternoon against probably the toughest opponent in the tournament, so I'm very happy."
Aljaz Bedene's 16-match winning streak was ended by Lucas Pouille in the final of the Hungarian Open.
The British number four had been unbeaten for more than a month, a run taking in two titles on the second-tier Challenger Tour and one of the best weeks of his career in Budapest.
But top seed Pouille was a step up in class on clay from his previous opponents and the Frenchman eased to his second ATP Tour title with a 6-3 6-1 win in just an hour and four minutes.
Pouille, who is at a career-high 14th in the world rankings, pummelled the Bedene serve, with the man ranked 68th winning just 25 per cent of points on his second delivery.
Bedene said: "I'm a little disappointed because I had problems with my finger and felt uncomfortable hitting my shots. I wasn't close to the level I should be at to beat Lucas, but he was playing really well. It was like everything went in for him.
"If I'm going to lose to anyone, it should be against someone who is a good player and a good person, which Lucas is."
Additional reporting by the Press Association.