Dublin, Ohio, June 1, 2013 (AFP) - Haas made an eagle and five birdies in a five-under par 67 that he completed on Friday to stand on nine-under 135 while Schwartzel, who opened with a 65 on Thursday, finished off a second-round 71 on Saturday morning to stand on 136.
American Kyle Stanley, also among 42 players on the course when play was halted on Friday, returned and finished a round of 70 to take third on 137, one stroke ahead of compatriots Matt Kuchar and Bubba Watson.
England's Justin Rose, Sweden's Robert Karlsson and American Scott Stallings shared sixth on 140 as the third round began early in hopes of finishing play before more storms were forecast to arrive Saturday afternoon.
A total of 73 players made the cut on three-over par 147, with defending champion Tiger Woods well back in his bid for a sixth title in the event hosted by Jack Nicklaus at Muirfield Village. Rory McIlroy is also struggling.
World number one Woods, already a four-time PGA winner this season, fired a 74 on Friday to stand 10 off the lead and stumbled early in the third round he began at the 10th tee with double bogeys at the par-3 12th and par-5 15th.
It was his second double bogey in as many days at 15 and it left him five-over for the tournament, next-to-last.
World number two McIlroy opened with a 78 but rallied to finish off a second-round 69 on Saturday to make the second half of the tournament on the cut line of 147, 12 strokes behind Haas.
Among those missing the cut was Chinese teen amateur Guan Tianlang, who slipped to a 79 on Friday after opening with a solid 72.
The 14-year-old prodigy won low amateur honours at the Masters in April, when he became the youngest player to compete at Augusta National.
He followed that up by making the cut at the PGA tournament in New Orleans, but missed the cut in the Byron Nelson Championship last month.
Scores on Saturday after the second round of the weather-disrupted US PGA Memorial tournament (USA unless noted, par-72):
135 - Bill Haas 68-67
136 - Charl Schwartzel (RSA) 65-71
137 - Kyle Stanley 67-70
138 - Matt Kuchar 68-70, Bubba Watson 71-67
140 - Robert Karlsson (SWE) 69-71, Justin Rose (ENG) 70-70, Scott Stallings 70-70
141 - Pat Perez 72-69, Hunter Mahan 73-68, Matt Jones (AUS) 69-72, Roberto Castro 71-70, Charlie Wi (KOR) 67-74, Scott Piercy 66-75
142 - Kevin Chappell 71-71, Charley Hoffman 73-69, Bo Van Pelt 73-69, Trevor Immelman (RSA) 70-72, Charles Howell 72-70, David Hearn (CAN) 71-71, Ryan Moore 70-72, Stewart Cink 70-72, Cameron Tringale 71-71, Davis Love 73-69, Graham DeLaet (CAN) 70-72, Carl Pettersson (SWE) 71-71