Chad Campbell, runner-up at the PGA Championship, disposed of Fredrik Jacobson, 6 and 5, while Tim Clark posted a 3-and-2 victory over Stephen Leaney. Thomas Bjorn was the only European to advance to the second round (Fri., 9:15 AM ET on TGC) after handling Len Mattiace, 4 and 3.
Singh was on fire early at the Wentworth Club and won the opening hole with a birdie. He added a birdie at the second for another win and took a 3-up advantage after Cejka bogeyed the par-4 third amid swirling winds.
The pair halved the par-5 fourth with birdies but Cejka found trouble with a bogey at the very next hole to fall 4-down.
Singh dropped a shot with a bogey at the seventh but regained his 4-up lead after Cejka bogeyed the 11th. Singh jumped to 5-up edge with a birdie at the 12th but gave a hole back to Cejka with a bogey at the 13th.
Singh put the clamps on the match with a birdie at the 17th and closed out the morning session with a birdie at the last to hold a 6-up edge after the first 18 holes.
Cejka's problems continued in the afternoon with a double bogey on the par-3 second. Singh added to that with wins at the fourth and the sixth to increase his advantage to 9-up en route to the dominating first-round win.
'I had a great start,' said Singh, who won this event in 1997. 'I was kind of worried about this match because I knew Alex was playing quite well and he also drives the ball very straight. He doesn't make many mistakes but I just told myself that if I go out there and do what I've been doing for the last three months, I should be okay.'
Singh will meet PGA champion Shaun Micheel in the second round.
'I wasn't even thinking about Shaun when I was playing today, but now I can look ahead and think what I have to do tomorrow because it will be a tough match.'
Campbell also had a hot start with wins at the second and the third before an eagle at the par-5 fourth put him 3-up over Jacobson.
The American was 4-up around the turn and managed to increase his lead to 5-up despite two bogeys on the back nine.
Campbell won his first two holes in the afternoon and added a birdie at the fourth to grab an 8-up lead.
Jacobson then bogeyed the ninth to fall 9-down before staging a late rally. Despite Jacobson's charge, it was only a matter of time before Campbell's early success translated into a rout.
'It was a good match but I was able to make a lot of putts where he didn't and I think that is what won it for me,' said Campbell, who will square off against British Open winner Ben Curtis in the second round.
Clark had a much more balanced match with Leaney and found himself 2-down at one point in the morning before battling back to square the match.
The South African fell 2-down again in the afternoon but grabbed a 1-up lead thanks to Leaney's stretch of three consecutive bogeys starting at the eighth.
Clark took a 2-up lead after Leaney bogeyed the 15th and dropped his approach inside 10 feet at the 16th. Clark then drained the putt to secure the match and advance to the second round where he will face none other than fellow countryman, and defending champion, Ernie Els.
'I think that is going to be more fun than anything,' said Clark. 'Obviously Ernie knows this place and he's playing really well. But I will go out and try and enjoy myself and maybe learn a little bit from him. I think I can put up a good match though.'
Bjorn also found himself trailing early and was 3-down after the morning session. However, the Dane, who lost the British Open with a late collapse, took advantage of Mattiace's struggles to take the lead in the afternoon.
Mattiace bogeyed four of his first six holes in the afternoon to let Bjorn back into the match. Bjorn obliged and birdied the eighth to go 1-up.
Bjorn's lead then grew to 2-up after Mattiace bogeyed the ninth. At the par- four 11th, Mattiace dropped another shot to fall 3-down.
Bjorn stretched his advantage to 4-up with a birdie at the 13th and held on for the win.
Bjorn will face Canada's Mike Weir, who ousted Mattiace in a playoff to win the Masters, on Friday.
'I am playing an awfully good player tomorrow,' said Bjorn. 'I'd like to focus on that before I start thinking about anything else.'