Spoiler Alert if you haven’t watched matches…

2ND UPDATE, 3:19 PM: Univision Deportes’ coverage of the World Cup group game yesterday snagged an average of 6.8 million total viewers and 3.5 million adults 18-49. As expected the Spanish-language network outgunned ESPN, which drew 4.2 million viewers on top of a 3.2 overnight rating that tied the overnight for the World Cup opener last week between Brazil and Croatia. Overall, Univision said 12.2 million total viewers tuned in to all or part of the broadcast, which aired on Univision Deportes and simulcast on Univision. The average viewer number set a record for Univision Deportes, besting the Mexico-France match (6 million) at the 2010 World Cup. Overall the tournament has been good to both ESPN and Univision: through 17 games, the former is up 28% in total viewers, and the latter is up 54% through today’s games. As for today’s matchups, expect strong numbers for Spain-Chile.

UPDATE, 9:12 AM: ESPN said its coverage of the Mexico-Brazil game last night drew a 3.2 overnight rating. Expect that to be dwarfed by Univision’s numbers which are still in the works, but that compares to the 7.0 rating ESPN saw for the U.S.-Ghana opener Monday night. The World Cup continues to score for ESPN though, with the first 17 games drawing a 2.9 metered market average. That’s up 26% from the 2010 World Cup in South Africa, thanks in part to host Brazil’s proximity to the States, with the late game kicking off close to primetime on the East Coast.

PREVIOUS, 4:44 AM: The most anticipated World Cup match-up last night was arguably the one between Brazil and Mexico. In the UK, it drew the second-biggest audience so far of the event with an average 8.48M viewers and a 39.1% share. The peak on BBC One was 11.3M. The network’s most-watched game is still England’s loss to Italy last weekend. In Brazil, it also wasn’t the tournament’s most watched: Early numbers from monitoring agency IBOPE say the match had a 34 share on Globo and an 8 on Band in the Sao Paulo area. The World Cup opener last Thursday, which saw Brazil beat Croatia, drew a 38 and a 9, respectively, for the same networks. Mexico is the team that has historically been the most successful against Brazil, and last night eight out of 10 Brazilian TVs were tuned in as the two played to a draw. Tonight, Australia faces off with Netherlands, Spain with Chile, and Cameroon meets Croatia.