British teenage tennis sensation Laura Robson crashed out of the Shenzhen Open in straight sets on Tuesday, a disappointing start to a year in which she is seeking to break into the world top 50.

The 18-year-old, currently ranked 53rd in the world, lost her second-round match against Romania's Monica Niculescu 2-6 3-6 in one hour and 16 minutes.

She was seeded seventh in the hard court tournament, and came into the contest ranked five places above her opponent.

Meanwhile, Chinese number one Li Na defeated Luxembourger Mandy Minella 6-4 6-0 in her first round match.

The 2011 French Open singles title winner and top seed will face American Julia Cohen in the next phase of the competition.

The Shenzhen Open -- carrying total prize money of $500,000 -- is being played for the first time as tennis expands in China on the back of Li's huge popularity. – AFP