Spanish tennis star Rafael Nadal has reached the semi-finals of the ATP World Tour Finals as well as ensuring he'll retain the year-ending number one ranking.
Nadal beat the Swiss Stanislav Wawrinka 7-6 7-6 on Thursday, after opening his campaign at the season-ending event in London with a 6-3 6-2 win over his weary countryman David Ferrer.
It's the third time Nadal has finished a year as number one, but the first since 2010.
The 13-time Grand Slam champion must be regarding 2013 as one of his most satisfying years of an illustrious career, which started after a seven-month injury break.
