Austrian international defender Alaba came off the bench and immediately scored from a 75th-minute free kick to give the defending Spanish champions a 2-1 come-from-behind win at promoted Almeria.

"Before I get into the game, he (coach Carlo Ancelotti) told me: 'Take this free kick, you are going to score,'" Alaba said.

"And then, after the goal, he said, 'Look, I told you.'"

After talking to the coach, Alaba sprinted from the bench and went straight to the free kick spot, then curled a well-struck shot that went over the wall and hit the post before going in.

"He is very good taking free kicks," Ancelotti said.

"The substitution came at the time of the foul and he is very good from that position. It was a very good shot."

Almeria, the Saudi-owned club promoted after seven consecutive seasons in the second division, had opened the scoring six minutes in through Belgian forward Largie Ramazani who slotted past compatriot Thibaut Courtois.

Madrid had been pressing since conceding and equalised with Lucas Vazquez from close range in the 61st minute. Vazquez had already had a goal disallowed for offside just before halftime.

Madrid on Wednesday began their season by winning the UEFA Super Cup 2-0 against Eintracht Frankfurt, when Alaba also scored.

Madrid won last season's Champions League and comfortably clinched the Spanish league title by finishing 13 points ahead of second-place Barcelona.

New Madrid signings Antonio Ruediger and Aurelien Tchouameni made their debuts as starters, with Luka Modric, Casemiro and Eden Hazard entering the match in the second half.

Elsewhere, Gennaro Gattuso debuted as Valencia coach with a 1-0 win against promoted Girona in a match in which his team played a man down during most of the second half.

Carlos Soler converted a penalty kick in first-half added time, then the hosts held on despite Eray Comert's sending off with a straight red card shortly after the break at Mestalla Stadium.

Takefusa Kubo, a 21-year-old Japanese attacking midfielder, made the most of his debut with Real Sociedad, scoring in the team's 1-0 win at Cadiz, for whom Socceroos winger Awer Mabil made his La Liga debut as a halftime substitute.

Sociedad finished sixth last season while Cadiz barely avoided relegation.

Australian Associated Press