Pedro latched onto Giorgian De Arrascaeta's cross to fire in a shot from close-range, just two minutes after Patrick de Paula had put his team ahead with a thumping 20-yard effort.
Juve went a player down in the 62nd minute as Adrien Rabiot was sent off after collecting his second yellow.
Betis' horrible night was completed eight minutes from time when Alissa Mandi was sent off for two yellow cards to leave his side to play out the final minutes with 10 men.
Greek fifth seed Stefanos Tsitsipas is among the other players through to the third round of the men's draw after he recorded a comfortable 6-1, 6-4, 6-2 win over Uruguay's Pablo Cuevas.
Chelsea boss Frank Lampard benched much-criticized goalkeeper Kepa Arrizabalaga and replaced him with Willy Caballero, but his side trailed 3-0 at the break as Callum Robinson netted in the fourth and 25th minute and Kyle Bartley made it 3-0 in the 27th minute.
BERLIN, Sept. 27 (Xinhua) -- Without a doubt, Schalke 04 faces one of the biggest crises in its history after their head coach David Wagner was sacked this Sunday morning.
MADRID, Sept. 27 (Xinhua) -- Ansu Fati scored twice and won a penalty with a magnificent first half performance as FC Barcelona beat Villarreal 4-0 in Ronald Koeman's debut as Barca coach.
Guangzhou Evergrande are chasing their ninth CSL title having dropped just eight points. But Fabio Cannavaro's side still have problems to solve on the defensive end, where ageing full-backs Li Xuepeng and Zhang Linpeng have raised questions whether they can stay healthy and consistent throughout the next stage.
1 Fati ready to become new Barca hero
FIFA's disciplinary committee found Trovato guilty of "manipulation of football matches and competitions" and of failing to collaborate with investigators.
Much more than their national rival Bayern, it seems that the Black and Yellow's team is full of apprentices trying to avoid slipping into further frustrations.