Real Madrid got a first half goal from Nacho and a solid defensive effort to keep Paris Saint-Germain at bay Tuesday night in the Estadio Santiago Bernebeu, their night's UEFA Champions League effort enough to book their spot in the knockout round of the competition while extending their current unbeaten run to 18 matches.

The 1-0 success was not easily accomplished against a PSG side that saw its own unbeaten run (23 matches) ended despite doing much of the attacking work against a home team missing both Gareth Bale and Karim Benzema upfront so concentrated on keeping things tight at the back.

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Malmo's loss at Shakhtar Donetsk meant that Real Madrid is safely through Group A while PSG remained four points clear of the other two in the section, just one win away from their own qualification for the knockout stage.

''They had a lot of possession and they also caused us problems on the counter,'' Madrid defender Sergio Ramos said. ''Today we got three very important points, but we have to keep on improving.''

Real Madrid has not lost in all competitions dating back to their semifinal Champions League loss against Juventus a year ago. PSG's last defeat came in last season's Champions League against Barcelona. Neither team had a conceded a goal in this season's group stage until Nacho broke the night's deadlock with his 35th-minute strike that came against the run of play in the battle of European giants.

Both managers had been forced to make significant first half lineup changes due to injury before the night's only goal arrived.

First, Laurent Blanc had to withdraw Marco Verratti in the 17th minute after the influential midfielder came out the worst of it after a tackle on Cristiano Ronaldo. Then it was Rafa Benitez' turn to lose a key player, the veteran Marcelo appearing to pick up a left leg hamstring problem in the 32nd minute. Benitez plucked Nacho as the replacement and got an instant reward from the player who decided the match.

''That's the way football is,'' PSG's Blanc said. ''We should have been more effective, but sometimes you score and sometimes you don't. The thing that bothers me the most is that Real Madrid scored the way it did. That play could have been avoided.''

Just two minutes after coming on, Nacho produced a fine, first-time vollied drive from an acute left side angle. The shot came after Toni Kroos' shot from the top of the box deflected off Thiago Silva and looped high into the air. Nacho ran onto the ball and had just enough control on his shot to beat Kevin Trapp as the ball nestled inside the far right post.

Before that goal, PSG had created the better chances, two of them falling to Zlatan Ibrahimovic. The Swedish international will probably think he could have better in the 22nd minute when he accepted a pass from Maxwell on the left, made some room by opening his body for the shot only to beat both Keylor Navas and the far right post. Six minutes later he flashed a 30-yard free kick over the wall, then saw the ball dip past the right post. Then it was the turn of Adrien Rabiot, who had replaced Verratti, to hit the post as PSG continued to be the more effective attacking side, but that momentum disappeared when the teams went in for the interval.

The Spanish giants obviously intended to protect what they had when the second half began, allowing PSG less space to work with than had earlier been the case and keeping enough of their foot on the gas to prevent the visitors from committing enough extra men forward.

PSG seemed unable to find a second gear so chances were rare after the interval. Cristiano was the lone pure attacker for Real, which only sent men forward when they had numbers on the counter-attack, refusing to be lured from their defensive posture.Try as they would, the French champions were not able to get Edinson Cavani any good looks while Ibrahimovic was also closely watched and kept under control.

When Angel Di Maria did carve a good opening with five minutes left his burst down the middle produced a pass that was cut out rather than a shot which might have gotten PSG level. Then Casemiro brought down Lucas Moura on the edge of the box two minutes later to give the visitors a gilt-edged free kick but Di Maria's shot got over the wall only to clip the top of the crossbar and fly away harmlessly.

''We delivered our best match of the season,'' Di Maria said after the loss. ''An outstanding display. We made a mistake and were punished. We played 10 times better than Real. We'll carry on that way.''

Shakhtar Donetsk 4, Malmo 0

Shakhtar Donetsk ended its European goal drought to beat Malmo 4-0 and sustain its slim hopes of qualifying for the Champions League knockout stages.

Shakhtar went into the game without having scored a goal in its three defeats so far in the group stage, but dominated from the start against the defensively-minded Swedish team. Oleksandr Hladkiy had several good chances before he put the hosts ahead in the 29th minute, heading in the rebound from his own shot.

Darijo Srna made it 2-0 from the penalty spot three minutes after the break, before goals from Eduardo and Alex Teixeira finished off the rout. Malmo finished the match with 10 men after defender Kari Arnason picked up his second booking.

Earlier, Malmo midfielder Oscar Lewicki was carried off on a stretcher wearing a neck brace after colliding with Shakhtar's Taras Stepanenko. Malmo said Lewicki had a concussion.

Shakhtar climbs above Malmo to third place in Group A after losing 1-0 in Sweden two weeks previously. Real Madrid beat Paris Saint-German 1-0 in Tuesday's other Group A game to advance to the knockout rounds. Shakhtar must win its final two games against Real and PSG to qualify, and that will be even harder with key defenders Srna and Oleksandr Kucher having picked up yellow cards against Malmo that mean both will miss the next game against Real.

Information from The Associated Press contributed to this report.