Arda Guler struck the only goal as Real Madrid won 1-0 at Getafe on Wednesday to claw back to within four points of LaLiga leaders Barcelona.
Barcelona inched closer to the LaLiga title with a 1-0 win over Mallorca on Tuesday which took them seven points clear of Real Madrid.
Flick said it was one of those comebacks that nobody forgets easily, adding it was not easy to win after Borja Iglesias netted a hat-trick to give Celta a 3-1 lead.
Barcelona will be aiming to open up a seven-point lead at the top of LaLiga table when they welcome Europe-chasing Celta Vigo on Saturday.
Barcelona coach Hansi Flick on Friday demanded to meet with La Liga officials over what he called a "joke" schedule, saying Spanish football was failing to take care of players.
Barcelona are through to the Champions League semi-finals with a 5-3 aggregate win, despite losing 3-1 at Borussia Dortmund on Tuesday with Serhou Guirassy hitting a hattrick.
Flick's side, undefeated in 24 games across all competitions, are not taking Dortmund for granted despite carrying a 4-0 advantage into the return at Signal Iduna Park.
Trailing 4-0 going into Tuesday's Champions League quarter-final return home leg against Barcelona, Borussia Dortmund coach Niko Kovac said his side can draw inspiration from Liverpool's 2018-19 comeback against the same opponents.
Barcelona extended their advantage in the Spanish top flight with a 1-0 win at Leganes on Saturday, completing a 12-match unbeaten run and moving seven points clear of second-placed Real Madrid.
Barcelona's last visit to face Benfica ended in a heavy thumping on the way to Champions League group stage elimination in 2021, but with young starlet Lamine Yamal propelling a team on the rise, hopes are far higher for the Catalans this time around.
Olmo has scored six goals and registered three assists in 18 appearances since joining Barca in the close season from RB Leipzig. The Catalans are second in the Champions League table, having won five of their six games.
The draw leaves the third-place Catalans five points behind leaders Atletico Madrid, who lost 1-0 at Leganes earlier in the day, but Hansi Flick's side could not take advantage.
Barcelona put in a clinical display to lift their first trophy in more than a year, having no silverware to show for last season.
Kylian Mbappe put Madrid ahead but a dominant Barcelona hit five in response before their goalkeeper Wojciech Szczesny was sent off in the second half.
LaLiga leaders Real recovered from that setback and are on a five-match winning streak ahead of defending the Super Cup in Jeddah, Saudi Arabia, but coach Carlo Ancelotti is cautious.
Last season, around this time, there was a surprise package in Girona in the top three of LaLiga. However, a year later, the Spanish league has returned to the status quo, with Real Madrid, Barcelona, and Atletico Madrid -- the three giants of Spain -- occupying the top three spots on the table at the end of 2024.
Jude Bellingham and Rodrygo scored second-half goals to help Real to a 3-0 win over Mallorca after Barcelona beat Athletic Bilbao 2-0 in the other last-four clash.
Gavi put Barcelona ahead from close range after 17 minutes and teenage winger Yamal netted the second early after the break.
Barcelona signed Olmo in August for around 55 million euros ($57 million), but with the club unable to meet LaLiga's wage capthe attacking midfielder and Spain international was registered only for the first half of the season.
