Tiger Woods battled through nausea, fever and vomiting to fire a three-under 69 on Saturday at the Hero World Challenge, his first tournament after a four-month injury layoff.
The former world No. 1 birdied the last three holes to stand on level-par 216 for 54 holes at Isleworth, but remained last in the 18-player field.
"It wasn't easy. I fought hard," Woods, who has shot lower scores the more ill he has felt, said in a hoarse whisper. "Spent all I had."
The American, who had not played competitively since the PGA Championship in August because of a back injury, vomited from the first hole onward, making six birdies and three bogeys on the day.
"I've been throwing up for hours," Woods said, noting that he has unable to keep food down or sleep well, but was not in pain and never considered quitting.
"I wasn't doing too good at the beginning but I thought I could hang in there.
"The fever just broke. As the round went on, I was starting to feel better."
Woods, who opened with a 77 on Thursday, fired a 70 on Friday with a fever, but was even worse off on Saturday.
"I didn't have nausea and vomiting before," he said, adding that his illness left him weaker.
"I just didn't have the explosiveness. I was pretty slow."
The 14-time Major winner, chasing the career record of 18 Majors won by Jack Nicklaus, has been hitting balls for only a month and has again revamped his swing by returning to a style from his younger days.
Woods turns 39 later this month - and no player has won four Majors beyond that birthday.
Runaway leader Jordan Spieth fired a bogey-free 63 to stand on 20-under 197, breaking the 54-hole Challenge record of Padraig Harrington in 2002 at Sherwood by one shot with a long birdie putt at No. 18.
The 21-year-old American stood seven strokes ahead of second-placed Henrik Stenson and Keegan Bradley, a Challenge record 54-hole edge, with Woods 20 shots adrift.
Woods has been solid and accurate off the tee the past two days, but his short game was awful and his putting has been spotty, a sign that fans might have to wait well into next year before he reaches competitive form.
His only hint about next year's schedule was that it would be a "probably slightly different" run-up to the Masters in April than normal.
At the first hole, he doubled over and vomited after hitting his approach 15 feet from the cup, but followed by making the birdie putt. He battled dry heaves but made a great chip to salvage par at the par-three second.
"I like to compete," Woods said. "If I can go, I can go. I'll give everything I have."