Joining Singh in the semi-finals are Colin Montgomerie, who defeated Padraig Harrington 5-and-3; Lee Westwood, who defeated Sergio Garcia 2-and-1; and Ernie Els, who bettered fellow South African Retief Goosen 2-and-1.
Each of the four higher seeds won on Friday, doing so with a combined aggregate of 46-under-par. Defending champion Montgomerie led the way by shooting an 11-under-par 61 over his first 18 holes to take a 5-up lead entering the afternoon 18.
Harrington played well Friday morning. In fact, the Irishman, who lost to Monty 7-and-6 in the semi-finals last year, won the first two holes. However, his 67 wasn't good enough to stay within earshot of Montgomerie.
Monty continued his assault on the Wentworth's West Course in the afternoon. Overall, the Scot was 15-under-par for the day, equaling Sandy Lyle's tournament record.
'If I had finished birdie-eagle in the morning I could have shot 59, but I was given the putt on the 5th,' said Montgomerie. 'That was the only stroke - a four footer - which didn't actually go in. I did, however, give it to myself.
'That round was up there with my best. Padraig made four birdies between the 3rd and the 18th and lost seven holes. When I drive in here it gives me a feeling of being 1-up. It's an amazing feeling.'
Montgomerie has won four of the last five times he has played on the West Course, including three straight Volvo PGA Championship titles. Monty will now face 1997 Match Play champion Singh. Singh was 11-under-par on the day in his thumping of Clarke.
Clarke came out early Friday morning to finish his first-round match with 43-year-old Nick Faldo. Faldo extended the match to 40 holes, before falling to the Ulsterman.
Singh was only 1-up through the first 27 holes, but won the 28th, 30th, 31st and 32nd holes to clinch a semi-final berth.
'Obviously, Colin is playing pretty good but I'm not playing too shabbily either,' Singh said. 'I played well today, especially in the afternoon. I am still taking painkillers for the arm injury I sustained in August, but it's getting better.'
In the bottom-half of the draw, Westwood will now face three-time Match Play champion Els. Two years ago, Westwood bettered the South African in the second round.
Both Westwood and Els survived close matches on Friday. Westwood shot 64 in the morning, but was just 1-up over Garcia. However, the Spaniard could get no closer in the afternoon, finally losing out to the Englishman 2-and-1.
Els and Goosen met for the first time since the two were juniors in South Africa. Els, who won this event in 1994-96, was leading his countryman by as much as 5-up. Goosen clawed back to get within 2-down, but lost out when both men parred the 35th hole.
Should Els and Singh both win on Saturday, it would set up a rematch of the 1997 finals, where Singh ended Els' three-year winning streak. If Monty and Westwood win, it would set up a much-anticipated match between Europe's best.
Said Westwood: 'Me against Monty? That would be fine by me, but I just want to play whoever is playing the better. That is what I want. I like to be tested.'