Shane Lowry could not build on his positive start and dropped out of contention at The Players Championship at TPC Sawgrass.
The reigning Open champion opened with a four-under 68 to share third place after the opening round, however, second-round 74 saw Lowry drop outside the top 20 in Florida.
Starting on the back nine, Lowry opened with four straight pars before dropping two shots before the turn, making bogey on the 14th and 18th holes.
The Clara man pulled a shot back on the par-four first hole before handing a shot back on the third to sit on two under for the tournament with six to play.
Lowry bounced back with birdie on the fourth hole before another shot was dropped on the seventh, and the former Irish Open winner ended with two pars and a share of 22nd on two under par heading into the weekend.
The third round will see Lowry begin seven shots off Lee Westwood's lead. The in-form Englishman shot 66 to take control of the tournament on nine under, one shot clear of compatriot Matthew Fitzpatrick who has hit consecutive 68s at the unofficial fifth major.
Chris Kirk and former Masters champion Sergio Garcia share third place on seven under par.
Rory McIlroy (+10) and Graeme McDowell (+3) were among the late starters on Friday and they both missed the cut with rounds of 75 and 74 respectively.
Westwood, who became European number one for the third time in December, said: "I believe I've played some of my best golf over sort of the last year and a half and I've had some good results against quality fields.
"A win in Abu Dhabi and then finishing second in Dubai end of last year to win the Race to Dubai was great playing under pressure and birdieing two of the last three holes.
"Last week I obviously played well under pressure again and this week I've carried it on.
"The nice thing for me about this week is not letting last week affect me in a negative way. I've regrouped. I've still got the memories of last week, of playing well and hitting good shots when I needed to, but there's no hangover from last week."