Serena Williams through to last four with 700th win

Serena Williams picked up her 700th career victory with a win against Sabine Lisicki that saw her through to the semi-finals of the Miami Open on Wednesday.

The American was made to work for the milestone triumph but eventually squeezed past her opponent 7-6(4) 1-6 6-3.

A thrilling first set saw Williams edge out Lisicki 7-4 in the tie-break before the German took control of the second with a dominant display, winning six straight games en route to evening the match up.

However, the world number one regained her composure to edge out Lisicki in the third before she was congratulated on the 700th win with a cake from the competition's organisers.

And that's career win No. 700 for @serenawilliams. Can you say Red Velvet? 🎂🎉 #MiamiOpen #vickysbakerycoralgables pic.twitter.com/4M5l05H1O9

— Miami Open (@MiamiOpenTennis) April 1, 2015

Williams told reporters after the match: "I had no idea [about the plans]. I saw them bringing a cake out and I was like 'Whose birthday is it?'

"But I really had no idea about it, so I'm really excited right now! I wasn't playing my best today, but some days you're just off, and that's when you have to fight.

"Even if I lost today, if I just gave 100% then I wouldn't have been upset."

The 33-year-old will now meet either Simona Halep or Sloane Stephens in the last four.