Seamus Power's closing-hole birdie pushed the Waterford man into the top six at the AT&T Byron Nelson in Texas.
Following an opening-round 65, Power posted a four-under 68 to sit in a tie for sixth place on 11-under, six shots off Sam Burns' lead at the PGA Tour event.
Starting on the back nine, Power made back-to-back birdies on his second and third holes before adding another on the 14th, his fifth, to make the turn at three under.
A bogey on the par-three fourth hole was the only blemish on the Olympian's card, and Power bounced back with a birdie on the seventh before closing out his round with another shot gained at the ninth hole to move to 11-under.
Padraig Harrington missed the cut as the Ryder Cup captain failed to build on his opening round 66.
The three-time major winner carded a second-round 75 to finish on three-under, three shots off the cut mark.
Burns meanwhile sizzled home with a 10-under 62. After making the turn at four-under for the day, the 24-year-old American birdied six of his last eight holes, starting with a 28-foot putt on the 11th, to move to 17-under for the tournament.
Swede Alex Noren shot a blemish-free eight-under 64 to sit in second place on 15-under, a shot ahead of South Korea's Lee Kyoung-Hoon, who carded a second successive 65.
Englishman Lee Westwood birdied five of his first six holes to make a charge up the leaderboard, finishing with an eight-under 64 to be in equal 22nd, eight shots off the pace.
Russell Knox was a further shot back at eight-under after a 67, two ahead of fellow Scot Martin Laird (66) and English veteran Luke Donald, who was two strokes off the lead after an opening 65 but stumbled with a one-over 73 to survive the cut by the barest margin.