Rory McIlroy carded 65 on Friday to sit one shot behind England's Marco Penge and Jacob Bridgeman of the US at the Genesis Invitational in Los Angeles.
The County Down man picked up three shots either side of the turn, including an eagle on the par-five 11th hole, en route to a total score of 11-under par headed into the weekend.
Shane Lowry improved considerably on an average opening day as he shot a 68 to move into a tie for 33rd.
The Offaly man made the perfect start with an eagle on the first, and was on course to go really low until his one and only bogey on the par-five 17th when his putter let him down.
Meanwhile, leaders Penge and Bridgeman both shot seven-under in the second round to hold on to a narrow lead.
Australian veteran Adam Scott had the best performance of the day, picking up two eagles and five birdies to head to the clubhouse on eight under, with a bogey on the final hole being the sole blemish.
Scott sits equal-fourth on nine-under par for the tournament, with the English duo of Matt Fitzpatrick and Tommy Fleetwood two shots further back.
Elsewhere, world number one Scottie Scheffler did just enough to make the cut, his second-round score of 69 enough to finish even par through the first two rounds.
