Sony Ericsson Open 2012: Watch Live Stream Online From Miami; Nadal, Murray, Azarenka, Venus Williams In Action, Wednesday Preview

When and Where: Singles action on Wednesday in the Sony Ericsson Open gets underway from Miami at 1 p.m. ET. A live stream is available via ESPN3. Live streaming coverage is also available through the tournament website with a subscription to TennisTV.com.

Preview: The men's quarter-finals get underway in the Sony Ericsson Open on Wednesday, while the WTA's semi-final lineup will be rounded out with the two remaining last-eight matches set to be played.

First up on Stadium court is Venus Williams against No. 5 seed Agnieszka Radwanska. Williams has looked in fine form in her first tournament since she revealed she is suffering with the rare autoimmune disease, Sjogren's Syndrome, at last year's US Open.

Already under her belt are victories over world No. 3 Petra Kvitova and former world No. 1 Ana Ivanovic.

And Radwanska would represent another significant scalp as the seven-time major winner looks to break back into the world's top 56 to earn qualification for this summer's Olympics.

The Polish 23-year-old has only lost to one player thus far in 2012, new world No. 1 Victorira Azarenka--four times.

Next up, Britain's Andy Murray takes the court against Serbian ninth seed Janko Tipsarevic. Despite a disappointing early loss in Indian Wells earlier in the month, Murray looks to have made positive strides in his vulnerable mental game with new coach Ivan Lendl by his side.

After a second-round defeat in Miami as part of a dismal run of results following last year's Australian Open, Murray knows that this week represents an excellent opportunity to gain valuable ranking points and close the gap on the world's top three.

Tipsarevic will be looking to kick-start his year after exiting in the third-round of both the Australian Open and Marseille so far in 2012. Murray, though, holds the slight edge in head-to-heads between the pair, 4-3.

After a giant scare in her last outing, Victoria Azarenka will be defending her unbeaten start to the year once more as she takes on Marion Bartoli in the last of the women's quarter-finals. The Australian Open winner trailed Dominika Cibulkova 1-6, 2-5 on Monday before she pulled it around to win 7-5 in the final set.

Although Bartoli defeated the Belarusian in last year's WTA Championships, as Azarenka's last match illustrated, she is now a completely different prospect on the tour. The newly found mental toughness, only amplified by the longer her current 26-match winning run continues, is going to be mightily difficult for any player to overcome.

Arguably the match of the day will be the last contest on court, not before 9 p.m., with Rafael Nadal taking on the explosive and charismatic Jo-Wilfried Tsonga.

Currently ranked No.6 in the world, Tsonga will fancy his chances up against Nadal, having beaten the Spaniard in the pair's last meeting at the Barclays ATP World Tour Finals last November.

Tsonga has shown that when he is focused, and his thunderous forehand is firing, he is a match for even the very best on tour and Nadal will likely have to show an improvement in the form that saw him exit meekly to Roger Federer in Indian Wells.