Porto announced the surprise signing of Luuk de Jong before going on to beat Atletico Madrid 1-0 in a pre-season friendly. De Jong was unveiled on the pitch ahead of kick-off on Sunday. The 34-year-old Dutchman joined Porto on a free transfer, having left PSV following the expiration of his contract. De Jong scored 14 Eredivisie goals last term, while supplying eight assists. He converted 14.3% of his shots, underperforming his league-leading 18.0 expected goals. The Dutchman then watched on as his new team overcame Atleti thanks to Victor Froholdt's goal on the stroke of half-time. Diego Simeone's side have been busy in the transfer market, though only two of their new additions – Matteo Ruggeri and Alex Baena – started. Atleti, who failed to progress to the Club World Cup knockout stage, only have one more pre-season friendly. They take on Newcastle United next week before they kick off their LaLiga campaign against Espanyol on August 17. Elsewhere on Sunday, Serie A champions Napoli went down 2-1 to Brest. Ludovic Ajorque netted twice for the French side, with Lorenzo Lucca on target for Napoli. The signing of De Jong is a significant boost for Porto, who are looking to improve their campaign next season. With De Jong's experience and skill, the Portuguese team may have a good chance of success. Additionally, the win over Atletico Madrid is a good sign for the team, who are looking to maintain their form and confidence for the next season. Porto's squad is looking strong, with De Jong's addition providing a new dimension to their attack. The team's fans will be eager to see how De Jong performs in the upcoming season.