By Brian Homewood TURIN, Italy (Reuters) - Juventus striker Carlos Tevez smashed home a second-half penalty as the hosts stunned holders Real Madrid with a 2-1 win in an absorbing Champions League semi-final, first leg on Tuesday. The irrepressible Argentine, playing some of the best football of his career, won the spot kick just before the hour when he was upended by Dani Carvajal on a breakaway and tucked it away to give Juve the edge after a pulsating, open game. The home side's Alvaro Morata scored against his old club, although he declined to celebrate, in the ninth minute but Cristiano Ronaldo headed the equaliser for Real in the 27th. Although Juventus are regarded as one of the most powerful clubs in Europe, Serie A's recent decline means they have been unable to keep up financially with the continent's elite and were regarded as relative lightweights among the semi-finalists. They were given a painful reminder of the gap two years ago when Bayern Munich beat them 4-0 on aggregate in the quarter-finals but Tuesday's win suggests they are back near the top. Giorgio Chiellini, booked for a crunching tackle in stoppage time, symbolised Juve's determination by playing the last few minutes with a bandage around his head after suffering a cut. Real began shakily and played well in patches though Sergio Ramos, once again moved up to midfield, looked uncomfortable, at one point spraying a cross-field pass aimlessly into touch, and Welshman Gareth Bale was subdued on his return from injury. "We made more mistakes than usual, not just Sergio, but at the back we had more difficulties because Juve put us under a lot of pressure but Sergio did a good job as he did in the past games," said Real coach Carlo Ancelotti. MORATA STRIKES Tevez had a hand in the opening goal when his shot towards the far corner was saved by Iker Casillas but went straight to Morata who tapped home. Real regained their composure and equalised when James Rodriguez cleverly flicked a bouncing ball over a defender for Ronaldo to head home at the far post. Ronaldo's goal meant the Portuguese regained the lead from Lionel Messi as the Champions League's all-time leading scorer with 76 goals, although the Argentine is in action for Barcelona against Bayern Munich in the second semi-final on Wednesday. The game could have turned out differently but Real forward James Rodriguez wasted a glorious chance when he headed against the bar from point-blank range before the break. Real fell behind again after an attack broke down. The ball was cleared to Morata who sent Tevez charging away and the Argentine's run ended in the Real penalty area where he was bundled over by Carvajal. Tevez got up to beat Casillas from the spot with a shot down the middle. The game continued to swing from end to end and substitute Fernando Llorente missed two good chances to put Juventus in an even stronger position. (Reporting by Brian Homewood; editing by Ken Ferris)