Des Smyth suffered a nightmare stretch in the middle of his round a slip nine strokes off the pace on his Champions Tour return in Florida.
Playing on a sponsor's invite after losing his fully exempt status last season, the Laytown and Bettystown man was two-under par after eight holes of the Allianz Championship.
But he dropped three shots in a four holes stretch from the ninth to card a one-over par 73 on The Old Course at Broken Sound near Boca Raton.
Smyth bogeyed the ninth and 10th and while he picked up a shot at the 11th, a double bogey six at the 12th followed by six straight pars left him tied for 50th as Jerry Pate and Bernhard Langer opened with eight-under par 64s to lead by a two shots from Fulton Allem.
Smyth, who celebrated his 56th birthday on the eve of the event, is warming up for the start of the European Seniors Tour season at The Aberdeen Brunei Senior Masters in Brunei Darussalam from February 27 to March 1.