Kiwi No 1 Danny Lee clawed back to square his World Golf Championship match on the second nine against Charl Schwartzel before slipping away once more and losing 1 down to the former Masters champion.
Lee was never in front at the Austin Country club in Texas as the opening games began in the five day event.
"Danny made a really good comeback, made a few birdies on the back nine," said Schwartzel.
"Then it felt like we both started playing a little scrappy and were just really hanging in there by the skin of our teeth. I'm just happy that I hit some good shots coming in."
Meanwhile Jason Day suffered a back injury in his opening round win over Graeme McDowell, potentially putting his Masters tilt in doubt.