Billy Horschel will go into the final round of The Open with a one-shot lead after carding a two-under 69 on Saturday, with Shane Lowry tumbling down the leaderboard.
Horschel leads a group of six players on three under, with Daniel Brown joined by Xander Schauffele, Justin Rose, Thriston Lawrence, Russell Henley and Sam Burns.
The American, who missed the cut at last year's tournament and has never finished higher than T21 at The Open, did well in blustery conditions at Royal Troon.
Horschel bogeyed the last after six straight pars, but a fine first nine featuring four birdies put him in a strong position as he chases his first major title.
Speaking to Sky Sports after completing his round, Horschel said: "This round in the Open Championship is by far the best one I've played in a major.
"I knew I had to grind out a score. I knew it wasn't going to be pretty, it was going to be tough... but I was prepared for what the last nine holes were going to entail.
"It would be the biggest win of my career. I have won a lot of great events, but this one would top all of them, and it's something I've always wanted in my golf career."
Having started the day at five under, Rose hung on in challenging conditions to stay within reach, while Brown – who has never won a tournament on the PGA Tour – found himself at six under after making a brilliant birdie on the 16th.
However, a double bogey on the last saw him lose the lead, a poor shot into the bunker leaving him with a 25-foot putt for bogey.
Despite an excellent showing, the 29-year-old was disappointed with the way he let his lead slip, telling Sky Sports: "That finish is a little bit frustrating.
"But at the start of the week, if you told me I was going to be one back going into the final round of The Open then I would have snapped your hand off!
"I've not really come here with any expectations... I've still got one round to go, I'm not going to get ahead of myself and start thinking about outcomes.
"I'm going to keep going about my business and hopefully come tomorrow evening, we will be there or thereabouts."
Further back, two-time major champion Scottie Scheffler is at two under after finishing even for the day, one stroke ahead of second-round leader Lowry, who endured a dismal third round.
Lowry carded a six-over 77, failing to recover from a double bogey at the Postage Stamp eighth as he found a deep bunker from the tee.