Real Madrid frustrated Arsenal to secure a 2-0 win in the first leg of the Champions League quarterfinals in Madrid.

Goals from Linda Caicedo and Athenea Del Castillo handed Arsenal their first defeat in the Champions League since the opening group-stage game where they lost 5-2 to Bayern Munich.

Caicedo split Arsenal's defence far too easily after a fumble from defender Leah Williamson allowed the young Colombia forward to take advantage and seal the win in the 21st minute.

Defensive frailty is a trodden path for Arsenal, who struggled at the back during the group stage and kept only two clean sheets in six games. They conceded nine goals before the knockouts but scored 17 in reply.

Meanwhile, Madrid scored the second most goals during the group stage (20), despite finishing second to Chelsea in their group.

The north London side struggled with their passing, allowing the hosts, who had spent much of the evening on top, to capitalise on their stumbles.

The substitutions helped improve chances but Arsenal lacked a clinical edge in the final-third to level the tie. Only one of their 13 shots were on target.

The visitors were clamouring for a penalty in the 67th minute after substitute Chloe Kelly was brought down by María Méndez but the referee was unconvinced.

Off the bench and against the run of play, Del Castillo ensured Madrid had their noses in front ahead of the second leg at the Emirates next week, slotting past Manuela Zinsberger with 10 minutes left to play.

After players voiced their negative opinion of the pitch at Pride Park during the League Cup final on Sunday -- where league rivals Chelsea beat Manchester City 2-1 -- complaints were made about the state of the pitch at Estadio Alfredo Di Stefano.

Arsenal legend Ian Wright wrote on Instagram: "Watching the Champions League quarter-final Real Madrid pitch, this is worse than Derby's pitch the other day. This is a f-----g disgrace the pitches these girls have to play on."

Madrid's Melanie Leupolz was forced off injured in the second half after losing her balance on the muddy and patchy pitch.

Arsenal are second in the Women's Super League and return to league action on Sunday to face Liverpool, who defeated them in the FA Cup quarterfinals.