Arsenal continued their winning start to the season with goals from Alexandre Lacazette and young striker Eddie Nketiah, who scored the winner five minutes from time after Michail Antonio had equalized for West Ham just before the break.
Beer Sheva's Dutch forward Elton Acolatse completed the scoring in the 83rd minute from Sintyahu Sallalich's assist.
Viera bagged his second with a stunning free kick in the 56th minute, before Cedric Bakambu added the fifth in the 85th minute.
Speaking ahead of his side's Carabao Cup game against Barnsley on Wednesday, Chelsea coach Frank Lampard said that former Chelsea goalkeeper Petr Cech, who is now a technical and performance advisor at the club, had been instrumental in the signing.
"It was very important to win our next match after the 5-0 defeat. The Copa Libertadores is not only about skill, it's also about heart. And the players showed that."
Despite their remaining ambitions, it was apparent that many of Bayern's cornerstones might soon need a short break to recover if they are to enjoy a successful campaign. Coming up is a stressful timetable containing two games per week for nearly the entire season.
"The Club has informed the relevant authorities and the player has been promptly placed in quarantine at home. All other team members and staff have tested negative," it added.
Granada continue their 100 percent start to the season that has seen them win two league games and qualify for the third qualifying round of the Europa League. Goals from Roberto Soldado and Darwin Machis gave Granada a 2-1 win at home to Alaves, whose goal was scored by Joselu.
Spain's 12-time French Open winner Nadal, who is bidding for a record-equaling 20th Grand Slam, will play world No. 83 Egor Gerasimov of Belarus in the first round.
Sport have secured three wins and a draw from their past five matches and are now 10th in the standings with 14 points, trailing Fluminense on goal difference.
The match went ahead and West Ham defeated their League One rivals 5-1 with assistant Manager Alan Irvine under charge.