Espanyol now travel to the Camp Nou for next Thursday's second leg having won and deprived Barca of a vital away goal.
"We knew we would lose one day", Barcelona midfielder Sergio Busquets said.
Barcelona boss Ernesto Valverde has said he expects Rafinha to play a big part this season, despite talk of a January exit.
Gerard Pique has called for better behaviour from fans in the second leg of Barcelona's Copa del Rey tie with Espanyol after some unsavoury incidents in Wednesday's match.
"It's not up to me to take action on these matters, but we hope the same things don't happen at Camp Nou", the defender added when asked about the incidents.
Luis Suarez was left out of the Barca line up, as Lionel Messi led the attack with Denis Suarez and Aleix Vidal.
London mayor calls out Trump's reason for cancelling United Kingdom visit
US President Donald Trump has canceled his trip to London with a tweet, in what appears to be a major diplomatic snub to Britain. Trump blamed the Obama administration for the move, accusing it of selling the old embassy for "peanuts" in a "bad deal".
Valverde said: "I liked my team a lot".
"I congratulate them and we'll meet again in a week's time". "The attitude was good and the players wanted to overcome the difficulties presented to them".
The return of Karim Benzema should boost Zidane's options across the front-line with the Frenchman expected to play for the first time in 2018 against Leganes.
"But their approach was to sit back and wait for us, closing any interior spaces". It was tough but we had it under control. "We have to accept the result". No other details about his injuries were made available.
Real struggled against a weakened Leganes team showing eight changes from the 3-2 La Liga defeat by Real Betis on Monday, indicating the host' lack of enthusiasm for the Cup despite supporters packing out their Butarque stadium.
- Raiders to host Seahawks in first NFL game at new Tottenham stadium
- Zac Efron as 'Extremely Wicked' Ted Bundy
- LaLiga: Gerard Pique extends Barcelona contract until 2022
- Two rape minor girl's corpse for hours in Haryana
- 'Canada's WTO complaint against USA could scuttle NAFTA'
- Retail Box leaks the specs of Samsung Galaxy S9 and S9 Plus
- Afghanistan to play first-ever Test against India in Bengaluru
- Venus Williams knocked out by Belinda Bencic
- NASA, USGS confirm MI meteorite strike
- City's unbeaten run in EPL ends with 4-3 loss at Liverpool