Manager Gerardo Martino has hailed Barcelona's "great performance" in demolishing Levante 7-0 and warned that it was just the start. Barca's passing and intense pressing overwhelmed the visitors as they romped to a 6-0 first-half lead thanks to goals from Alexis Sanchez, Lionel Messi (2), Dani Alves, Pedro and Xavi. Martino, 50, then introduced Brazilian international Neymar for his debut after the break and could even afford the luxury of withdrawing Messi with 20 minutes remaining before Pedro rounded off the scoring for the evening with the seventh. "The first-half performance was great," the Argentine manager said. "The concepts we wanted to improve we have improved, but it was nothing new. They were things from the past that we have returned to doing. We scored a goal from pressing high, played both through the middle and on the wings, but we have only just started." Martino said he had agreed that it will be better for Messi to rest in the final stages of such one-sided games this season. "He is very intelligent and we came to an agreement very quickly in this sense. I spoke to Leo a few weeks ago and we chatted about the importance of various matches and he understood that it was good to rest." Martino said. "Resting a little in many matches is the equivalent to resting a full game. In a tight game, I wouldn't take him off. It would be crazy to do so." Another of Barca's star performers on the evening was Cesc Fabregas as he was heavily involved in several goals and Martino stressed he would be an important player this season after the club turned down the advances of Manchester United to keep him at the Camp Nou. "He had a good pre-season tour in Asia and he is very good because he gives us a lot of options. He creates goals and arrives very well into the box," the manager said. Real Madrid manager Carlo Ancelotti was a relieved man after Isco's late header handed his side a 2-1 win over Real Betis, but warned his side had a lot of improving to do. "I think we can improve, which is normal. We had many chances to score and a lot of good combinations, especially on the wing," said Ancelotti, who has taken over from Jose Mourinho. "The problem was in defence. In the first half we didn't work well together and we had a lot of problems. "It was a problem of balance. There was a lot of space between our defence and midfield and Betis played very well in this area. If we want to play quality football, we need players like Isco and [Mesut] Ozil to do defensive work."