Walter, who replaced Christian Alves in the 83rd minute, latched onto Jonathan Cicero's cross and needed just one touch before rifling a shot into the bottom right corner.
In the opening game, the Viola scored the winner in the 78th minute as Gaetano Castrovilli tapped in from Federico Chiesa's assist.
Nadal, seeded second, lost 6-2, 7-5 to eighth-seeded Schwartzman, who will next play 12th seed Denis Shapovalov of Canada for a spot in the final.
In addition, the Shanghai Pudong Football Stadium has been put into service on Tuesday. The stadium, with 33,765 seats, will make its debut at the final of the 10th season of League of Legends (LPL) World Championship, known as S10, on October 31.
"We are working hard for the new season and I think we will have the same group of players that we have now in pre-season," he commented.
"We're going to call on the Brazilian Football Confederation (CBF) to make the Maracana an alternative to the beach," Rio mayor Marcelo Crivella told reporters. "Today the biggest problem Rio faces are the big crowds of people with no masks at the beach."
Stage One involves 32 groups of four players, with the player who tops each group progressing to Stage Two.
Moreno's goal was exceptional as he controlled the ball in the Eibar area before turning, leaving his marker and scoring with a shot to the far post. Alcacer kept his cool after beating the offside trap.
The result means Rafa Benitez's side are sixth in Group A, three points off the fourth place, while Shanghai Shenhua slip to the fifth position in the group on goal difference. Both teams have chances to advance to the championship group for the second stage of Chinese Super League with five games remaining.
Eight minutes later, things went from bad to worse for Duisburg as Volkmer felled Erling Haaland as the last man to receive his marching orders.
New Betis coach Manuel Pellegrini made his presence felt as his side defended much better than they did last season in their 1-0 win away to Alaves last week, while Valladolid were slightly unlucky to only draw 1-1 at home with Real Sociedad.