The result also means second-placed Real Sociedad can reclaim top spot if they beat Eibar on Sunday.
Holders Real Madrid chased away some of their early-season blues when Gareth Bale scored the pick of the goals in a 5-1 rout of FC Basel in their Champions League Group B opener on Tuesday.
A summary of Tuesday's matches in the UEFA Champions League.
Real Madrid became La Liga champions for the first time since 2012 on Sunday with a 2-0 win at Malaga, denying arch-rivals Barcelona three consecutive league titles.
Vietto slotted the ball home with seven minutes to go after Karim Benzema had given visitors Real the lead early on.
Mats Hummels scored with a header in the 14th minute to give Germany a 1-0 victory over France in the first quarter-final of the World Cup at the Maracana, in Brazil, on Friday.
Gijon spoiled Asier Illarramendi's return to Real Sociedad's midfield after rejoining from Real Madrid this week when they held the Basque club, coached by Scot David Moyes, to a 0-0 draw in San Sebastian.
Images from football matches played across Europe on Sunday.
Images from the Champions League matches played on Wednesday
Real Madrid can bury Atletico's hopes of winning La Liga with a third straight victory against their city neighbours on Sunday that would leave the capital's second club trailing by six points.
When Juventus coach Massimiliano Allegri was greeted with a hail of eggs and spat at on his first day at work he could not have imagined he would lead them to the brink of an unprecedented treble of titles in his first season.
Barcelona wrap up 23rd La Liga crown with Lionel Messi goal.
Cristiano Ronaldo, Gareth Bale and Karim Benzema took Real Betis apart to give Real Madrid a resounding 5-0 win on Saturday that put them level on 50 points with Barcelona and Atletico Madrid at the top of La Liga.
Juventus shattered Real Madrid's dream of a record-extending 11th European crown when Alvaro Morata scored against his former club to secure a 1-1 Champions League draw with the holders on Wednesday and send Juve into the final 3-2 on aggregate.
Real Madrid closed to within three points of La Liga leaders Barcelona and Atletico Madrid at the halfway stage of the season when a Pepe header secured a laboured 1-0 win at mid-table Espanyol on Sunday.
The Portuguese forward then fired in the penalty in the sixth minute of stoppage time.
A red hot Luis Suarez scored four goals and contributed three assists as Barcelona's stuttering La Liga title charge sparked back to life with a spectacular 8-0 thrashing of Deportivo La Coruna on Wednesday.
A lethal finish from Luis Suarez gave Barcelona a 2-1 victory over Real Madrid in a typically frantic 'Clasico' on Sunday as they stretched their lead over their rivals at the top of La Liga to four points.
Centre forward Eder, who scored the winning goal in the Euro 2016 final against France, was among 10 players from that squad omitted from Santos's list. Other unlucky players included midfielders Andre Gomes and Renato Sanches, forward Nani and defender Eliseu.
Benzema to stand trial in sex tape case, says lawyer.
Eden Hazard finally scored his first goal for Real Madrid as his side beat second-placed Granada 4-2 in a highly entertaining game at the Santiago Bernabeu on Saturday to go four points clear at the top of La Liga.
Barcelona forward Ousmane Dembele scored twice and produced a mesmerising display to fire his side to a 5-1 win over Villarreal on Wednesday which stretched the champions' unbeaten run this season to 36 games with two remaining.
Photos from the La Liga matches played on Sunday
Luka Modric pulled one back for Zinedine Zidane's shellshocked side with a brilliant strike from distance early in the second half before substitute Vinicius Jr reduced the deficit to one goal.
Cristiano Ronaldo struck twice as leaders Real Madrid subdued Eibar 4-0 on Saturday while Lionel Messi set a La Liga record of 253 goals with a hat-trick in second-placed Barcelona's 5-1 rout of Sevilla.
Real Madrid and Barcelona pulled two points clear in La Liga when Cristiano Ronaldo set a club scoring record in Real's 3-0 stroll against Levante and Neymar hit four as Barca beat Rayo Vallecano 5-2 on Saturday.
Cristiano Ronaldo continued his prolific start to the season with four goals, including two penalties, as Real Madrid came from behind to beat Elche 5-1 in La Liga on Tuesday.
Real Madrid's unbeaten start to the La Liga season came to an abrupt and surprising end as Real Mallorca claimed a stunning 1-0 victory at a rocking Son Moix on Saturday to climb out of the relegation zone.
Barcelona closed in on the La Liga title by thrashing local rivals Espanyol 5-0 on Sunday as Atletico Madrid dropped out of the race after losing 2-1 at Levante and Real Madrid beat Valencia 3-2.
News of all that's transpired on and off the football field
Real Madrid produced a gutsy performance to earn a 1-0 win at Sevilla, on Sunday, which took them level on points at the top of La Liga
Images from Tuesday night's UEFA Champions League group stage matches.
Real Madrid's Javier Hernandez struck twice as they came from behind to beat Celta Vigo 4-2 away and keep the pressure on Barcelona at the top of La Liga on Sunday.
Barcelona must appreciate matching the club's record of nine wins and a draw in their first 10 games of a Liga campaign, especially after Real Madrid's defeat at Girona, coach Ernesto Valverde told a news conference on Monday.
Images from the Champions League matches played on Tuesday
A round-up of Sunday's matches in La Liga, Serie A and Bundesliga.
Real Madrid's stuttering season continued as they were reduced to 10 men and then slumped to an 11th La Liga defeat of the campaign by going down 3-1 at Real Sociedad.
Lionel Messi reclaimed the FIFA Ballon d'Or award for the world player of the year on Monday from his great rival Cristiano Ronaldo who had walked off with the award for the previous two years.
Luis Suarez struck twice and Lionel Messi scored on his 500th appearance for Barcelona who set a new Spanish record of goals in a calendar year with a 4-0 win over Real Betis that lifted them top of La Liga on Wednesday.
Real Madrid ensured top spot in La Liga at the midway point of the season when Cristiano Ronaldo struck twice in a 3-0 win at Getafe on Sunday before Lionel Messi's hat-trick helped Barcelona to a 4-0 victory at Deportivo La Coruna.