Jurgen Klopp warned that Liverpool must remain "on alert" despite putting one foot in the Champions League final with a dominant 2-0 win over Villarreal in the first leg of their semi-final tie at Anfield on Wednesday. Two goals in two minutes undid Villarreal boss Unai Emery's defensive game plan as Pervis Estupinan deflected Jordan Henderson's cross into his own net before Sadio Mane slotted in a second. 

The Reds remain on course for an unprecedented quadruple of Champions League, Premier League, FA Cup and League Cup. And barring a huge upset when the sides meet again in southern Spain in six days' time, Liverpool's season will finish with a third Champions League final in five seasons in Paris on May 28. "It is 2-0 at half-time," said Liverpool boss Klopp. "You have to be completely on alert, 100 percent in the right moment and play the second half like we played the first.