By Jude Summerfield Barcelona wonderkid Lamine Yamal became the youngest goalscorer in El Clasico history as his side thrashed Real Madrid 4-0 at the Bernabeu. Saturday night’s visitors navigated an even first half before firing out of the traps at the start of the second period, with Robert Lewandowski’s brace quick brace putting them in complete control. The La Liga leaders protected their lead well and added to it in the 77th minute when Yamal went streaking through on the right and finished high at Andriy Lunin’s near post. It meant he became the youngest ever scorer in the fixture’s long …