Rafael Nadal began his bid for a sixth Madrid Open title with a comfortable win over birthday boy Carlos Alcaraz to reach the last 16. Nadal, who returned to No 2 in the world last week after his thrilling win over Stefanos Tsitsipas in the Barcelona final, thrashed his 18-year-old opponent 6-1, 6-2 in the Spanish capital. Fans at Manolo Santana Stadium sang ‘happy birthday’ as the Spaniard stepped onto the court against his countryman and childhood idol. He was also presented with a cake to mark the occasion but that was the end of the festivities as ruthless Nadal took charge. Ranked 120 in the world, Alcaraz battled bravely and even broke his compatriot Nadal's serve in the second set but was predictably overwhelmed by one of the game's greats in a match that lasted one hour and 17 minutes. Nadal will take on Australia's Alexei Popyrin in the next round after he defeated rising Italian star Jannik Sinner 7-6, 6-2. Clay king Nadal last week secured his 12th Barcelona Open title when he battled to a marathon 6-4, 6-7, 7-5 victory over Tsitsipas Nadal already has his eyes on a record-extending 14th French Open triumph, where victory this year would also edge him ahead of Roger Federer's 20 major titles and to the top of the all-time men's list. "The victory in Barcelona helped me a lot. Things have got better since," said Nadal, reserving special praise for his vanquished opponent. "He's a youngster who is coming on strongly, who has enormous potential, and the only thing he needs is time." Earlier, second seed Daniil Medvedev, returning to the circuit <a href="https://www.thenationalnews.com/sport/tennis/daniil-medvedev-out-of-monte-carlo-masters-after-testing-positive-for-covid-19-1.1202772">after testing positive for Covid-19 in mid-April</a>, picked up his first win on clay for two years when he came back from a set down to beat Alejandro Davidovich Fokina 4-6, 6-4, 6-2. The Russian has always struggled on clay. In four attempts, he has failed to get past the first round of the French Open. Nor has he won a match in Rome while this was his first win in Madrid in his third appearance. "I love clay," he said ironically into the camera at the end of the match. In total, the 2021 Australian Open finalist has only 11 wins on the surface although he will have the chance to make that 12 when he takes on Christian Garin in last 16. "I think Madrid is a little faster than other clay tournaments, so better for my game," he said after his win. German fifth seed Alexander Zverev swept past Kei Nishikori of Japan in straight sets 6-3, 6-2 and will now take on Dan Evans. The unseeded Brit battled his way from a set down to defeat John Millman of Australia 6-7, 6-2, 6-3. World No 9 Diego Schwartzman was dumped out by Aslan Karatsev 2-6, 6-4, 6-1. Russian Karatsev will take on Alexander Bublik in the next round.