Francisco Arce's reign as coach got off to a winning start as a first-half blitz saw Paraguay stun South American champions Chile 2-1 in CONMEBOL World Cup qualifying.
Back at the helm for a second spell after Ramon Diaz resigned following Paraguay's group-stage exit at the Copa America Centenario in June, all eyes were on Arce and his men in Asuncion on Thursday.
And Paraguay produced a stunning upset, scoring twice inside the first 10 minutes to send their opponents back to Chile empty handed, Oscar Romero and centre-back Paulo da Silva leaving the visitors reeling amid pandemonium in the stands at Estadio Defensores del Chaco.
Arturo Vidal reduced the deficit nine minutes before half-time but Chile were unable to find an equaliser, losing Gary Medel to a late red card and slumping to a third defeat from seven World Cup qualifying fixtures, as Paraguay moved two points above the back-to-back Copa America winners on 12 points.
There were considerable changes to both teams, who were playing for the first time since the Copa America in June, with no less than seven new faces introduced by Arce following Paraguay's 1-0 loss to the United States at the tournament.
Chile were without goalkeeper and captain Claudio Bravo, but they still had Vidal, Alexis Sanchez and Eduardo Vargas as Juan Antonio Pizzi made four changes to the side that beat Argentina in the final of South America's premier international tournament.
Despite Chile's intimidating trio on show, the visitors were left shellshocked as Paraguay made a dream start with two goals inside the opening 10 minutes.
Romero broke the deadlock with a stunning long-range strike in the sixth minute, after collecting the ball from outside the penalty area, turning his opponent and unleashing an unstoppable effort into the top corner of the net.
Paraguay continued to run riot three minutes later as Da Silva manoeuvred himself into a position from a corner to head the ball past Cristopher Toselli from inside the six-yard box.
Chile eventually settled into the match, stemming the flow, though their defence still appeared vulnerable.
And the Chileans managed to claw their way back into the contest as Paraguay dropped deeper and deeper, Vidal meeting Charles Aranguiz's free-kick and glancing a header past Diego Barreto in the 36th minute.
Paraguay started the second half like they did the first, but without managing to score.
Romero almost restored Paraguay's two-goal lead four minutes after the interval, however, his low shot was turned around the post, while Dario Lezcano was unable to keep his effort underneath the crossbar just seconds later in a wasted opportunity for the home team.
Chile thought they had equalised via Sanchez but their joy was cut short after the goal was ruled out for offside with 23 minutes remaining as Paraguay held on.