Sanz and Nieto are playing their first and last tournament together, having played a single event in 2022 as well - where they would end up lifting the Torrent Challenger title.
The young Spaniards beat six-seed Belasteguin and Yanguas, having already eliminated Sanyo Gutierrez and Momo Gonzalez on Thursday.
Sanz will fight to reach his first-ever Open final on Saturday, although he and Nieto will have to get past Arturo Coello and Agustin Tapia.
Watch the quarter-final highlights below!
