Dredge led by four at that point and was never seriously threatened again. The Welshman played the final 15 holes in 1 under as he closed with a 4-under 67 to finish eight clear of the field.
The 33-year-old ended at 17-under-par 267 and collected his second tour win. Dredge claimed his first win at the 2003 Madeira Island Open and has now won two of the five times he has led after three rounds.
'It was a little bit of everything. I feel like I am playing a little bit better, I'm thinking better, I'm putting a little bit better and all those things add up to scoring better, which is what I am doing,' explained Dredge.
'For me really, the key was to starting well this week. I was just happy to start well after last week (tied for 18th at BMW International Open) and just keeping the whole thing rolling.'
Marcel Siem, who played alongside Dredge, struggled to a 2-over 73 to end in a share of second at 9-under-par 275. He was joined there by Francesco Molinari (69).
Sergio Garcia, the 2005 champion, managed an even-par 71 Sunday to finish tied for fourth at minus-8. He was joined there by Soren Kjeldsen (70) and Marc Warren (67).
Dredge wasted little time in putting pressure on the rest of the field, and Siem especially. Siem entered the round two back, while Oliver Wilson was the next closest, four back.
The Welshman two-putted for birdie on one. Then Dredge drained birdie putts on two and three, both from over 25 feet, to extend his lead over Siem to four.
Dredge parred his next six holes and during that stretch, it started to look like he was playing an ocean course instead of in the mountains at Golf Club Crans-sur-Sierre.
He saved par from greenside bunkers on seven and nine. At the 10th, Dredge sank an 8-footer for birdie. He made another 8-footer on 11 and found himself seven clear of Molinari.
Dredge parred his next four holes. He landed in greenside bunkers on three straight holes from the 14th, and it cost him on 16. He blasted out safely, but two-putted for bogey. He calmly parred the final two holes for the easy win.
'I've been working really hard on my game,' said Dredge. 'I'm beginning to hit the ball solid week in and week out. I've been easier with myself and that's really been helping out the last few weeks. I've made a couple more putts recently and that's one area that has consistently let me down in the past.'
Siem, like Dredge, birdied the first. However, he dropped a shot on the sixth to fall five back. Siem got that shot back when he two-putted for birdie on the ninth.
The German hit over the green at the par-3 11th and struggled to a double-bogey from there. Siem dropped another shot on 13 when he could not save par from a bunker.
Siem birdied the par-5 14th for the fourth day in a row. He tripped to bogey on 17 and missed a birdie putt at the last that would have given him second place alone.
Molinari was making a nice run on the front nine. He birdied the fifth, then eagled the short par-4 seventh for the second time this week. That got him to minus-10, six back of Dredge, but just one behind Siem.
The Italian cooled as he parred five consecutive holes from the eighth. He moved to 11 under thanks to a birdie on 13, but slid back to minus-9 with a double-bogey on the par-5 15th before parring out.
Mikko Ilonen, Ariel Canete and Cesar Monasterio all closed with rounds of 5-under 66 to end tied for seventh at 7-under-par 277. They were joined there by Martin Erlandsson and Andrew McLardy. Phillip Archer also shot 66 in the final round and was one of five players a shot further back at minus-6.