Cristiano Ronaldo's back-to-back Champions League hat-tricks have established yet another parallel with Lionel Messi.
The pair now have seven hat-tricks apiece in the Champions League after Ronaldo followed up his treble in Real Madrid's dramatic quarter-final win over Bayern Munich with another against Atletico Madrid on Tuesday.
Here, Press Association Sport looks back over the Real and Barca stars' magnificent sevens.
Ajax 1 Real Madrid 4, October 3, 2012 (Group stage)
Ronaldo's first European treble came as he and Karim Benzema put Real two up and the Portuguese added fine goals in the 79th and 81st minutes.
Galatasaray 1 Real Madrid 6, September 17, 2013 (Group stage)
Isco and Benzema laid the platform before Ronaldo's second-half hat-trick secured Real's biggest away win in the Champions League era.
Real Madrid 4 Shakhtar Donetsk 0, September 15, 2015 (Group stage)
Benzema opened the scoring and Shakhtar had Taras Stepanenko sent off before Ronaldo converted two penalties and a late header.
Real Madrid 8 Malmo 0, December 8, 2015, (Group stage)
Having opened the Group A campaign with three goals, he rounded it off with another four for a record group-stage tally of 11.
Real Madrid 3 Wolfsburg 0, April 12, 2016 (Quarter-final)
Trailing 2-0 from the first leg, Real needed their talisman to step up. He levelled the tie by the 17th minute with two quickfire goals before his second-half free-kick found a way through the wall.
Real Madrid 4 Bayern Munich 2, April 18, 2017 (Quarter-final)
Real led 2-1 from the first leg and though Ronaldo cancelled out Robert Lewandowski's penalty in the second, Sergio Ramos' own goal took the tie to extra time. Bayern's Arturo Vidal was sent off, though, and Ronaldo scored twice more in the extra period, in the process moving past 100 Champions League goals.
Real Madrid 3 Atletico Madrid 0, May 2, 2017 (Semi-final)
He picked up where he left off as his team routed their city rivals. Ronaldo headed in Casemiro's cross in the 10th minute, with Atleti appealing for offside, and scored twice more in the last 20 minutes.
Barcelona 4 Arsenal 1, April 6, 2010 (Quarter-final)
The Argentina star scored all four as Barca, having drawn the first leg 2-2 and then fallen behind to Nicklas Bendtner's goal, roared back to win. Gunners keeper Manuel Almunia was reduced to a helpless stooge by Messi's deft brilliance.
Viktoria Plzen 0 Barcelona 4, November 1, 2011 (Group stage)
A 24th-minute penalty brought Messi his 200th Barca goal and he then scored in stoppage time in either half, with Cesc Fabregas also on target.
Barcelona 7 Bayer Leverkusen 1, March 7, 2012 (Last 16)
Messi was not done in that season, his most prolific ever with 73 goals in 60 games including 10 hat-tricks in all. He scored a remarkable five, the first player to do so in the Champions League era, as the Blaugrana completed a 10-2 aggregate rout of their German opponents.
Barcelona 4 Ajax 0, September 18, 2013 (Group stage)
Messi and Ronaldo each began their respective 2013-14 campaigns with three goals, the Barca man responding to his rival's effort the previous night with a sumptuous free-kick in the first half and two more goals in the second.
APOEL 0 Barcelona 4, November 25, 2014 (Group stage)
Luis Suarez's first Barca goal became a mere footnote as Messi moved clear of former Real Madrid favourite Raul as the Champions League's all-time leading scorer - a record he and Ronaldo would dispute for years to come.
Barcelona 7 Celtic 0, September 13, 2016 (Group stage)
Messi set the tone with an early opener and a well-worked second before sliding home his third and Barca's fifth on the hour mark. He added a late assist for Suarez's second of the night.
Barcelona 4 Manchester City 0, October 19, 2016 (Group stage)
Jordi Alba and Gerard Pique were injured before half-time but Messi was not worried, scoring from Fernandinho's error in the 17th minute and killing the game off after half-time.