Loupe, a professional golfer for three years, qualified for the tour through the Web.com circuit last season and this is his sixth tournament. He has missed the cut in all of the other five.
He shot an 8-under-par 63 on the Monterey Peninsula course, one of three used for this event. Monterey Peninsula is a par-71 course while the other two layouts in the rotation, the Pebble Beach Golf Links and Spyglass Hill, are both par 72.
Loupe, 25, who played his college golf at LSU, lowered his previous-best score on the tour by four shots. He posted a 67 in he opening round of the Humana Challenge on Jan. 16, but still missed the cut.
The five lowest scores on opening day were all turned in at Monterey Peninsula. Stuart Appleby, Jim Renner, Scott Gardiner and Richard H. Lee all shot a 6-under 65. Fed Ex Cup points leader Jimmy Walker was also at 6-under, but that put him at 66 after he played his first round at Pebble Beach.
The opening round was delayed for 3 hours during the morning by steady rain, after which the sun came out and play progressed until it became too dark to continue. There were 38 players still on the three courses when play was suspended.
Mickelson had three holes yet to play at Monterey Peninsula and his round was highlighted by an eagle at the par-5 sixth -- his final hole of the day.