Arsenal defender David Luiz has made a number of costly blunders in his career, but he was at his best in the FA Cup semi-final at Wembley.
David Luiz dazzled in Arsenal's FA Cup semi-final win against Manchester City - delivering a performance hailed as "fantastic" by Rio Ferdinand and Robin van Persie.
Former England centre-back Ferdinand and ex-Arsenal striker Van Persie saw David Luiz produce a series of priceless tackles, blocks and interceptions in a 2-0 victory for the pre-game underdogs.
The Brazilian made 11 clearances, Opta statistics showed, and looked rock solid as he, Shkodran Mustafi and Kieran Tierney formed a resilient back three.
"He was the standout performer," Ferdinand told BT Sport. "Every cross that came into the box, he was the man on the end of it most of the time, heading and putting his body on the line.
"Defensively he didn't put a foot wrong. When he plays in a three at the back - he did it under [Antonio] Conte as well at Chelsea - he looks a much better player.
"You get the security of numbers in terms of having two other defenders immediately alongside you as a centre-back, and it decreases the space between you.
"So it is easier for him but you can't take anything away from him: he was fantastic today."
Ferdinand described defence as "the area where they've always let themselves down" and an "Achilles heel" for Arsenal in recent times.
If it was surprising that Arsenal should keep a clean sheet against a City side that beat them 3-0 in June, it was made more so by it being David Luiz setting the standards at the back - given his error-strewn showing in that previous encounter concluded with a red card.
Ferdinand said: "He's come in for a lot of criticism in the last couple of seasons and a lot of it rightly so at times. He's made a lot of mistakes and you get criticised for that. Today I think the way they set up helped him.
"Three centre-backs, they packed out the middle of the pitch, and they played with a defensive security. There was a stability about the way they played. They were composed defensively and they had a sharp edge on the counter-attack.
"When they went forward - minimal times over the course of the game because they were pushed back - they looked like a team who were very dangerous and capable of scoring and they got two very good goals."
Van Persie also found much to admire in David Luiz's game, having feared Arsenal faced "a tough evening".
"Tonight he put his body in front of the balls he was blocking," Van Persie said.
"I think he headed away maybe 25 balls tonight. He was absolutely fantastic."