Not many 9-year-olds can say they walked alongside Lionel Messi at the World Cup game where he became the tournament's leading goalscorer. But Santi Cruz Melo can. Ahead of Argentina's group-stage game against Austria at Dallas Stadium on Monday, 9-year-old Melo was selected to walk out with Argentina, and it turned out to be a day hell never forget. "I heard the teacher say get in two lines and I ended up in the front," Melo told FOX 4, the local Dallas-Fort Worth affiliate. World Cup walkouts start with the teams captain in the front, followed by the goalkeeper. Melos first in line paired him with Messi. Once Melo realized who he was paired with, he knew he was in the presence of the best in the world. "Hes the best player in the whole entire universe," Melo said of Messi. "I got to be calm, I was not going to freak out, like I just got to be calm. Then he walked out besides me, I stuck out my hand and he held it and we walked out." This World Cup marks Messis sixth total World Cup, and the GOAT is in pursuit of defending Argentinas 2022 title. What Melo also got to witness after standing beside Messi was his historic performance. His one goal against Austria put him in a category of his own: the World Cups all-time leading goalscorer, among men and women, with 18 total goals. Although Messi and Melo did not exchange words, Messis kind smile was the perfect gesture to make Melos day even better. "This is so cool," Melo said. "Im walking out with Messi. This is a once-in-a-lifetime experience. Probably one of the best days of my life." Messi and Argentina have already clinched Group J and a spot in the round of 32. Argentina will close out group stage play against Jordan on Saturday at Dallas Stadium.