Cabrera and Pettersson shot 7-under 65 in calm conditions Thursday morning to set the pace before the first round was suspended by a thunderstorm.
Only 51 players completed play before the horn sounded at 1:27 p.m. Tournament director Steve Timms said the storm dumped about 1 1/4 inches of rain, leaving shallow ponds on many of the fairways.
"You just can't play under the rules of golf with that much casual water," Timms said.
Grounds crews fanned out across the course late in the afternoon, and Timms was optimistic that Redstone would be playable when the first round was scheduled to resume at 7:30 a.m. on Friday.
"Let it drain overnight, and I think it will be just fine," Timms said.
Ricky Barnes and Jeff Maggert completed their rounds in the morning and were one shot off the lead. Brian Harman also was 6 under, but had three holes left.
Defending champion Phil Mickelson, Fred Couples and Ernie Els, who needs a victory to qualify for the Masters next week, were playing their front nines when play was suspended.
The Houston Open became the run-up event to the Masters in 2007. Timms is hoping to finish the tournament by 5 p.m. Sunday to accommodate not only television, but also the players heading to Augusta.
"We do everything we can operationally to hit that window," Timms said.
The morning groups enjoyed sunshine and calm conditions.
Pettersson birdied four of the first six holes, then reached the par-5 eighth in two and two-putted to reach 5 under. He added birdies on Nos. 11 and 15, then found the greenside bunker with his approach on No. 17 en route to a bogey.
Pettersson missed the cut the last two weeks at Innisbrook and Bay Hill and blamed poor iron play. He changed his setup on the range Tuesday and hit 16 of 18 greens in regulation Thursday.
"I felt confident with that, but that doesn't always relate to good play," he said. "But I felt like I was striking the ball well again, and I told myself just to play aggressive and shoot at the pins and see what happens."
The big-hitting Cabrera birdied three of the four par 5s, and rolled in a 22-foot, downhill birdie putt on the 18th hole.
"The course is perfect," Cabrera said before the storm. "It's really spectacular and it's right for making a good score."
The two-time major champion has missed the cut in four or five PGA Tour starts this year. But Charlie Epps, his Houston-based swing coach and the director of golf at Redstone, says Cabrera has rounded into form in recent weeks.
"He got off to a slow start and he's been working hard and it's coming on," Epps said. "He's been close in a couple of tournaments. It takes time."
Cabrera has played at Redstone every year since 2007, the year he won the U.S. Open. He missed the cut here in 2009, then won the Masters the following week.
Epps said Cabrera is concentrating on this week and not thinking about the Masters just yet.
"He wants to play well this week, he's focused on this week," Epps said.
Barnes overcame a bout of food poisoning early in the week. He skipped the pro-am Wednesday, but felt fine Thursday morning.
"I got a lot of rest, lot of fluids in me," Barnes said. "And I feel good, and I'll probably be able to get a little workout in later in the day."
The 48-year-old Maggert, who lives in Houston, is winless in 23 starts in his hometown event. The 66 on Thursday is his lowest competitive round at the Tournament Course at Redstone.
"Kind of struggled a little bit since we moved to Redstone, but hopefully this week, I can turn it around," Maggert said. "It was a fun day. I felt some confidence on the greens today, and I made a few putts early and (it) kind of carried over for the rest of the day."
Chris Kirk, who tied for second behind Mickelson last year, withdrew Thursday morning to attend to a personal matter.
The tournament was delayed by bad weather for the first time since 2009.