* Stenson remains in front, despite back-nine struggle
* Still on track to win Tour Championship, FedExCup title
* Woods a distant 14 strokes off pace (Adds quotes, detail)
By Mark Lamport-Stokes
ATLANTA, Sept 21 (Reuters) - Henrik Stenson retained his four shot lead in the season-ending Tour Championship despite dropping four shots in torrential rain over the closing holes of Saturday's third round.
With the FedExCup playoff title and a bonus jackpot of $10 million also on the line at East Lake Golf Club, Stenson carded a one-under-par 69 in difficult scoring conditions to stay on track for all those honours.
The Swede, ranked second in the FedExCup points standings, raced to the turn in four-under 31 to briefly lead by nine strokes but dropped four shots on the back nine to post an 11-under total of 199.
Long-hitting Dustin Johnson, who narrowly squeezed into the elite field of 30 players, fired a 67 to sit alone in second place at seven under, two ahead of fellow American Steve Stricker (68).
FedExCup points leader Tiger Woods, seeking a sixth PGA Tour victory this season, was a distant 14 strokes off the pace after returning his first sub-par score this week, a 69.
"I think I'll choose to look at it from the bright side even though the weather is not that bright at the moment," Stenson told reporters.
"Started the day with a four-shot lead and I've still got it, so that's all that matters really. I had it going, and I had a much larger lead than that for a while.
"Then the rain came, and I started hitting a couple of loose ones on the back nine. It was just hard. It was just a grind to get finished. I'm happy we got the round done."
Asked how much he was focused on winning the FedExCup title, Stenson replied: "First of all, I'm interested in winning the tournament, and I know, if I do that, then I'm going to win the FedExCup. We're just trying one more day."
Stenson's playing partner, Masters champion Adam Scott, tumbled out of contention with a 74 after falling ill. The Australian was suffering from flu and a high fever and was put on an intravenous drip before he teed off.
"The way I was feeling this morning, without the doc's help, I definitely wouldn't have been going," said Scott, who had been alone in second place overnight, four strokes off the lead.
"I started feeling good about four holes to go. I'm disappointed that I wasn't at 100 percent to try and give Henrik a shake and stick with him."
The players teed off extra early on Saturday with tournament organisers concerned about heavy thunderstorms expected later in the day and Stenson, competing in the Tour Championship for the first time, made a sizzling start for a third consecutive round.
The in-form Swede, who won the Deutsche Bank Championship earlier this month, knocked in a three-footer to birdie the second and a 20-footer at the third to move seven strokes ahead.
Stenson rolled in a seven-foot birdie putt at the seventh, then picked up another shot at the par-five ninth, where he chipped up to two feet, to reach the turn with a commanding nine-stroke lead.
As the rain intensified amid strengthening winds, the Swede dropped his first stroke of the day at the 10th after missing the fairway off the tee and hitting his second back left of the green.
He also faltered at the 14th, his tee shot sailing way left for his ball to settle under a bush from where he had to take an unplayable lie, but limited the damage by sinking an 11-footer for bogey.
Stenson recovered with a birdie at the par-five 15th, getting up and down from a greenside bunker, and did well to salvage par at the tricky 17th where he rolled in a 15-footer.
However, he signed off with a three-putt bogey at the par-three last for his lead to be trimmed to four.
"It was tough to finish, and I hit a couple of bad shots," he said.
U.S. Open champion Justin Rose of England (70) and Americans Zach Johnson (69), Jordan Spieth (71) and Billy Horschel (70) were tied for fourth at four under. (Reporting by Mark Lamport-Stokes; Editing by Julian Linden)