A few bad iron shots and a little desert heat just aren’t huge challenges any more.

Lewis persevered through more triple-digit temperatures to shoot a 3-under-par 69 at the Kraft Nabisco Championship yesterday, opening a three-stroke lead over Yani Tseng, Brittany Lincicome, and Jane Park.

Michelle Wie shot a 67, matching the day’s best round in Rancho Mirage, Calif., and closing within six shots in contention for her first major title. Tseng, the defending champion and the world’s top-ranked player, shot a 68. First-round co-leader Lincicome mustered a 72 to stay one stroke ahead of Morgan Pressel and Amy Yang.

The leaders all managed to thrive on dry, speedy greens during a second windless day at Mission Hills, with the temperature topping 100 degrees by midday.

But Lewis pulled ahead at 9-under 135 after several big putts during the second round, smoothly reaching the halfway point of the LPGA Tour’s first major in strong position to chase her first victory during what’s expected to be a cooler weekend.

“My round was all over the place,’’ said Lewis, who shared the first-round lead. “But I made some really good up-and-downs and stayed really patient on the back nine, and I was fortunate to get away with a couple of pars that I probably shouldn’t have.’’

Lewis and Wie memorably went to the same LPGA Q-school in December 2008. While Wie’s presence got all the headlines, Lewis had the five-round event’s best score.

Wie was 2 over in Thursday’s first round, but she rallied impressively yesterday morning after a horrible start. Her first tee shot flew into the gallery and beaned a little girl.

“I never felt so horrible about a shot ever,’’ said Wie.

PGA — Tour rookie Chris Kirk shot a 3-under 69 to take a one-stroke lead over defending champion Anthony Kim and 2008 winner Johnson Wagner after two rounds of the Houston Open at Humble, Texas.

Kirk was 9 under, and played his last few holes just as the wind picked up in the afternoon and made scoring more difficult. Kim and Wagner took advantage of calm morning conditions. Kim shot a 64, the lowest round of the day, and Wagner had a 67.

Padraig Harrington, first-round leader Jimmy Walker, and Josh Teater were two shots back at 7 under.

Organizers groomed the Tournament Course at Redstone to simulate conditions that players will see at the Masters next week, and the setup lured many of the world’s top players to Houston.

Phil Mickelson (70) and Lee Westwood (72) were part of a large group at 4 under and Ernie Els (72) and Fred Couples (72) were among the players at 1 under.

The cut fell at even par, and former Masters champions Jose Maria Olazabal and Angel Cabrera were among those who failed to make the weekend.

Kirk, second on the Nationwide Tour money list last year, birdied two of his last three holes to take the outright lead and make up for a double bogey on the par-5 fourth.

Champions — Jeff Sluman tied a Fallen Oak course record with a 6-under 66 to take a one-shot lead over Tom Lehman at the Mississippi Gulf Resort Classic in Saucier.

Sluman had a bogey-free round, highlighted by an eagle from 154 yards on the par-4 fourth.

European — Joost Luiten (69) and Rhys Davies (70) shared the lead midway through the Trophee Hassan II event in Agadir, Morocco, at 6-under 137. First-round leader Peter Lawrie shot a 76 to fall three strokes off the lead.