Andy Murray blasted out on clay as Raonic's rocket hits the target

Murray admitted he was unhappy with his backhand, which is usually so reliable

Andy Murray stretches to make a return during his straight-sets defeat (AP)

Do not try telling Andy Murray that clay courts fail to bring the best out of the game's big hitters. Seven days after being outgunned by Tomas Berdych in the quarter-finals of the Monte Carlo Masters on his first appearance of the year on clay, Murray went out at the same stage of the Barcelona Open in similar fashion yesterday.

This time his conqueror was Milos Raonic, who won 6-4, 7-6 to earn a place in today's semi-finals against David Ferrer.

Raonic, who made his breakthrough last year, has been considered a major threat on fast courts, but the 21-year-old Canadian is enjoying a remarkable week on clay. In the previous round he knocked out Nicolas Almagro, who had won more matches on the surface than anyone else this year, while his victory over Murray was his first over a player ranked in the world's top eight.

Murray, who had looked in good shape after dropping only eight games in his first two matches, never got to grips with Raonic's cannonball serve, which he was facing for the first time. No player on the tour can match Raonic's record in winning 93 per cent of his service games this year.

Raonic, who has already won two titles this year, dropped only four points on his serve in the first set, during which he hit eight aces. Murray, who lost his own serve in the seventh game, won only one out of the 16 points in which Raonic put his first serve in court.

The second set was closer. Murray started to make inroads into the Canadian's serve, only to drop his own at 4-4. In the next game, nevertheless, he broke Raonic for the only time before the set went to a tie-break. However, Murray eventually lost it 7-2 when he put a backhand in the net.

Murray confessed that he had not been happy with his backhand, which is usually the most reliable part of his game. He said he had difficulty returning Raonic's serve but was pleased with the improvement he had made in the second set.

Raonic, who trains in Barcelona with his coach, Galo Blanco, said he was still learning how to play on clay. "I have to play more matches and gain more experience," he said. "But the victory today is definitely good for my confidence on clay, especially because hard courts are my favourite surface."

After a busy start to the clay-court season, Murray will concentrate on practice next week before playing back-to-back Masters Series tournaments in Madrid and Rome. He will then go on to the French Open, which begins in four weeks' time.

Ferrer is through to the semi-finals after a marathon match of 15 minutes short of three hours against his fellow Spaniard, Feliciano Lopez, Ferrer winning 6-7, 7-6, 6-3. In yesterday's later quarter-finals, Rafael Nadal beat Janko Tipsarevic 6-2 6-2, while Fernando Verdasco went through when Kei Nishikori retired with an abdominal injury.