Tiger Woods has been knocked out of the Accenture World Match Play in Tucson, Arizona by his fellow American Nick Watney.
A missed birdie-put on the fifth ultimately cost the former world number one his place in the next round.
Watney will face Lee Westwood, who triumphed 3&2 over Sweden's Robert Karlsson.
Rory McIlroy also progressed with the same margin against Denmark's Anders Hansen.
Meanwhile, Martin Laird and Paul Lawrie will meet in an all-Scottish last-16 tie after wins over Italy's Matteo Manassero and Japan's Ryo Ishikawa.
Last-16 ties:
Peter Hanson vs. Kyle Stanley/Brandt Snedeker
Mark Wilson vs. Dustin Johnson
Martin Kaymer vs. Matt Kuchar
Steve Stricker vs. Hunter Mahan
Rory McIllroy vs. Miguel Angel Jimenez
John Senden vs. Sang-Moon Bae
Lee Westwood vs. Nick Watney
Martin Laird vs. Paul Lawrie
