Angelique Kerber misses the chance to regain the world number one ranking with defeat by Elina Svitolina at the Dubai Championships.
British number three Kyle Edmund beats Lu Yen-hsun to set up a Delray Beach Open quarter-final against Milos Raonic.
US Open champion Stan Wawrinka and in-form Grigor Dimitrov will be in the line-up for the Aegon Championships at Queen's Club in London in June.
Eighteen-time Grand Slam champion Roger Federer signs a new three-year deal to play at the Basel event until the age of 38.
Audio & Video
Judy Murray and speakers from women's sport and sport media launch She Rallies - a plan to boost women's tennis across the UK.
Tom Fordyce sees the world's ninth and 17th-ranked players defy age and injury to produce an Australian Open contest to number among the greatest ever.
How to get into Tennis
How to get into tennis - a sport on the up in the UK. Find your nearest court and learn the basics with our guide
What's on BBC Sport this week
This week's sport on the BBC includes the Six Nations, Super League, skeleton and boxing, plus the Premier League and EFL Cup.
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