Ernie Els chased down David Toms and won the 2010 PGA Grand Slam in impressive fashion at Port Royal yesterday.

The South African came from three shots back to win by a stroke, as his putting, which had let him down for 30 of the 36-hole event, finally clicked.

Els rattled in a 15-foot birdie putt at 14, having just watched Toms chip in for the second time in three holes to save par, and then, after a birdie at 15, putted from off the green at 16 to move a shot ahead.

In contrast, Toms, who was scrambling from 13 onwards, dropped a shot at 15 and all of a sudden found himself behind.

The American might still have levelled matters at 17 but after Els drained a clutch putt from 10 feet to save par, Toms left his uphill birdie effort agonisingly short.

Any hopes he might have had disappeared when he drove into the fairway bunker on 18 and Els completed a solid par to take first place and the $600,000 winner's cheque.

"I was struggling on the greens a bit yesterday (Tuesday)," said Els. "I was struggling on the greens again today until let's say the last five, six holes when I found something in my putting stroke.

"My speed came back. I made some really big putts. Those are the putts that I was missing almost a day and a half, then they started dropping and that was the difference."

Toms led for much of the day as he had for most of the tournament, and was well in control after a turn that saw him move three shots clear.

The American began his second round in much the same way as he had his first, finding the flag with an unerring ease. However, like Els, his putter deserted him on occasions, and he reached the turn at level par for the round after a birdie at seven was cancelled out by a bogey at nine.

Still, with Els carding bogeys at the first and nine, along with a birdie at seven, Toms had a two-shot lead going to 10.

By the time they reached the 12th green, Toms was only a shot ahead after Els had birdied 11. But the American then chipped him from the back of the green for birdie, and when Els missed his birdie chance, Toms seemed destined to win.

That sense of destiny was further re-enforced when Toms repeated his chip shot on the 14th, this time rescuing par after he had found deep rough off the tee. Even with Els birdie-ing the hole, the South African was still two shots back.

"I thought when a guy does it once (chip in) you're thinking, good shot," said Els. "When he does it twice in three holes, you're thinking maybe he's destined to win this thing.

"To be honest, it took a bit of the pressure off me in a way where I free-wheeled it from then on. I was just trying to see how close I could get to him.

"He made a mistake on 15. I made birdie, he made bogey. That was a big change."

From three shots back, Els found himself level, and when he drained a 35-foot putt from off the green on 16, and Toms made par after finding the bunker off the tee, Els had turned the deficit into a one-shot lead.

"I guess I had the lead for the last, I don't know, 29, 30 holes," said Toms. "Sometimes that's really hard because everybody else is just kind of winging it.

"And on a day like today you're playing safe, trying to hit the smart shot, hanging in there as much as you can.

"I think early on if I would have made some of those birdie putts, I had some early on, but the back nine, you're hanging on. I felt like I didn't necessarily lose this thing. Ernie birdie-ing 14, 15 and 16, the putt he made on 16, I'd say he won the tournament.

"For me, to go through those holes, play them under par would have been a pretty good feat in itself. He played them three-under."

While Els and Toms were battling it out for first, Graeme McDowell and Martin Kaymer were having a battle of their own, to not finish last.

McDowell started the day one-over, two shots ahead of Kaymer, and a birdie, birdie start gave him a faint of hope of catching the leaders.

However a bogey at four, a double-bogey at seven, and back-to-back bogeys at 13 and 14, saw him fall back to three-over.

Kaymer, meanwhile, finally put some red on his scorecard after dropping to five-over, and birdies at 15 and 17 pulled him level with McDowell as they went down 18. A par apiece left them tied for third, which gave both $225,000 for their two days' work.

"There's an element of pride kicks in," said McDowell, "No one wants to finish last for sure.

"It was tough, when you're completely out of the mix, it's very difficult to keep the pedal down, but we (McDowell and Kaymer) had a nice little tussle the last four or five holes. It was a lot of fun."