The Bears' first line of defense Saturday night was composed mainly of second-line players who could not stop the Phoenix Cardinals' offense when it counted.
The Cardinals roared to a 20-3 lead by the end of the third quarter and held on for a 20-17 preseason triumph in sultry Sun Devil Stadium.
Rookie quarterback Will Furrer rallied the Bears to a fourth-quarter touchdown for the second straight weekend, but the Bears' defense could not stop Phoenix.
Chris Zorich, James Williams, Tim Ryan, Eric Kumerow and Alonzo Spellman saw extended time in the middle of the defensive line. Aside from a few outstanding plays, they were generally overmatched.
The heat was on the Bears from the start of the game as the game-time temperature was 110 degrees. But the temperature on the field at game time was measured at 141 degrees.
Robert Balling Jr., director of the office of climatology at Arizona State, said the players would be under severe weather stress even if they wore only T-shirts and shorts.
"You're putting big boys out on a field with 20 pounds of equipment on them," he said. "Clearly, that person is going to undergo a lot more stress. There's no doubt when a guy goes out to play football in (very hot) weather, there will be fairly substantial heat load and stress."
Both teams were provided 1,600 pounds of ice and sideline air conditioners.
Veteran Cardinals left tackle Luis Sharpe warned the Bears before the game: "It's the hottest game you'll ever play."
Cardinals quarterback Timm Rosenbach, who missed last season with a serious knee injury, completed 13 of 13 passes for 150 yards and three touchdowns in last weekend's 35-14 preseason win over the San Diego Chargers. "It's just preseason," said Rosenbach before Saturday's game. "I wish the San Diego game meant something. It means I'm doing the things I need to do well for us to win. But I wish I could get more excited about it. I wish it was a regular-season game."
Rosenbach continued his preseason perfection in the opening drive Saturday, completing two passes, including a 53-yard toss to Ernie Jones for a touchdown over cornerback Donnell Woolford. Greg Davis' extra point made it 7-0.
The Bears drove to the Cardinals' 8-yard line at the start of the second quarter, but a 10-yard holding penalty pushed them back to the 18. Then Jim Harbaugh's rollout pass intended for Tom Waddle was intercepted by cornerback Aeneas Williams and returned 31 yards to the 34.
Waddle injured his right knee on the play, but returned on the Bears' next possession.
Rosenbach promptly directed the Cardinals on an eight-play, 66-yard drive capped by a 23-yard screen pass to former Bear Johnny Bailey for a touchdown and a 14-0 lead.
Cardinals backup quarterback Chris Chandler directed the next scoring drive of 52 yards, which resulted in a 44-yard field goal by Davis and a 17-0 lead with 58 seconds left in the half.
The drive included a 27-yard pass from Chandler to rookie tight end Derek Ware.
Harbaugh completed 10 of 15 passes for 114 yards in his first-half stint. Waddle had four receptions for 54 yards. Harbaugh was intercepted once.
Rosenbach was 7 of 9 for 118 yards and two TDs. Anthony Thompson ran for 64 first-half yards on 10 carries for the Cards.
The Cardinals amassed 239 total yards in the first half to the Bears' 143.
Quarterback Paul Justin started the second half for the Bears. Second-stringer Peter Tom Willis did not dress for the game after getting sick in Friday night's team meeting.
Justin led the Bears on an eight-play, 62-yard drive that resulted in Kevin Butler's 35-yard field goal with 10:16 left in the third quarter.
Darren Lewis gained 41 yards on four carries during the drive.
The Cardinals countered the Bears' three-pointer with a 42-yarder by Davis for a 20-3 lead late in the third quarter.
Justin and Lewis hooked up on a 68-yard pass for a touchdown at the start of the fourth quarter. Butler converted to cut the deficit lead to 20-10.
"The big issue has been that I don't have breakaway speed," Lewis said. "This was just to show the people I do have speed."
Furrer took over in the Bears' next series and directed the offense on a 10-play, 67-yard scoring drive.
Furrer passed four yards to Ron Morris for the TD as the Cardinals had only 10 players on defense. Butler's conversion with 6:32 to go made it 20-17. The Bears' Mike Ditka is the fourth-winningest active coach in the NFL with a .652 winning percentage. His overall mark of 107-57 includes six division titles. But he entered Saturday night's game with a 22-22 preseason record.
"We want to win. There is no fun in going out and losing a game. But mainly you want to improve, get better," said Harbaugh. "It didn't really kill the Washington Redskins to only win one of their four preseason games last year. So how important is it to win in the preseason?"