MADRID - Kylian Mbappe's second-half penalty earned Real Madrid a hard-fought 1-0 home victory over Osasuna in their opening LaLiga game of the season on Tuesday, giving Xabi Alonso a winning start in his first league match in charge of the hosts.

After struggling to break down a stubborn Osasuna defense in the opening half, Mbappe won the penalty and converted from the spot six minutes after the break to give Real the lead, but the home side were unable to increase their advantage.

"In the first half we didn't have space and then in the second half we scored early," Mbappe told Real Madrid TV.

"We had more chances and we had more control, we expected to score the second but it didn't come."

The visitors had Abel Bretones sent off in added time for a foul off the ball on Gonzalo Garcia as Alonso's side got their league campaign off to a winning, but underwhelming start as they look to wrestle back the league title from Barcelona.

Alonso's side, whose last competitive game ended in a 4-0 defeat to Paris St Germain in the Club World Cup semifinals, completely dominated against a visiting side clearly content to sit back and perhaps come away with a draw, which they almost managed.

Real enjoyed plenty of possession in the opening 45 minutes with lots of slick passing, but their only real chances came through shots from distance, with Eder Militao's powerful strike forcing Osasuna keeper Sergio Herrera into a decent save.

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All Osasuna's defensive work was undone shortly after the break when a foul by Juan Cruz on Mbappe was punished with a penalty, and Real's French forward stepped up and sent the keeper the wrong way as the hosts finally found the net.

The goal forced Osasuna out of their shell somewhat, while Real pushed to find a second goal to kill the game off, with Arda Guler unleashing a shot from outside the area which zipped just over the bar.

Alonso, who started the game with three of the club's new signings -- Trent Alexander-Arnold, Dean Huijsen and Alvaro Carreras -- in his back four, then sent on 18-year-old Argentine midfielder Franco Mastantuono for his Real debut.

Mastantuono almost made an immediate impact, with his effort from a wide angle saved by Herrera at his near post. Minutes earlier, Osasuna had their chance to snatch what would have been an undeserved equaliser but Ante Budimir headed over from inside the six-yard box.

"It was important for us to start with a win at home, we knew it was going to be difficult," Mbappe said.

"Osasuna had a clear plan to wait for us and they had Budimir. We are happy with the victory and we are going for more."

With Barcelona beating Mallorca 3-0 in their opening game on Saturday, three points were already a must for Alonso, and he did it without the injured Jude Bellingham, Ferland Mendy, Eduardo Camavinga and Endrick, as well as the suspended Antonio Ruediger.