Spain's Rafael Cabrera-Bello defeated Korea's Byeong Hun An to book his place in the quarter-finals of the WGC-Dell Match Play on Saturday, and with it a Masters debut next month.
An inspired Cabrera-Bello was about to move five up with six to play when An signalled on the 12th green that a neck injury meant he was unable to continue their last-16 tie at Austin Country Club.
And that meant Cabrera-Bello was assured of winning enough world ranking points to move inside the top 50 in time for the final qualifying deadline for the year's first major championship on Monday.
The 31-year-old was already two up when he holed a bunker shot on the eighth and also birdied the ninth from six feet, and was facing an eagle putt on the 12th when An - who had found the water with his approach - conceded the match.
American Chris Kirk defeated compatriot Bill Haas 2&1 to reach the quarter-finals, where he will face world number three Rory McIlroy after the defending champion secured a hard-fought victory over Zach Johnson.
McIlroy, who lost the opening hole after duffing a chip, bounced back to win the next two holes before a par on the fourth was enough for Johnson, who succeeded McIlroy as Open champion last year, to get back on level terms.
A par on the eighth edged McIlroy back in front but he three-putted the 10th and then saw Johnson hole from 35 feet on the 11th for birdie and save par on the 12th after finding water with his approach.
However, Johnson then made a mess of the 13th and 15th and although he won the 16th with a birdie and holed from 20 feet for another on the last, McIlroy's superb approach had left him just three feet for birdie to seal victory.