AMES, Iowa -- Kansas coach Mark Mangino pulled his Jayhawks together at halftime and gave it to them straight. He figured they were bound to start playing better, because they couldn't play any worse.

" 'We've played very poorly,'" Mangino said he told his team, which trailed 20-0 at the break. " 'But we can win this game, and we will win this game, if you keep your poise, you stay calm.'"

The Jayhawks did just that, answering an awful first half with one of the biggest comebacks in school history.

Todd Reesing threw for 319 yards and three touchdowns and No. 16 Kansas stormed back from a 20-point hole before hanging on to beat Iowa State 35-33 on Saturday.

Kerry Meier caught seven passes for 125 yards and two TDs for the Jayhawks (4-1, 1-0 Big 12), who tied the third-biggest comeback in school history by outscoring the Cyclones 35-13 in the second half.

Iowa State (2-3, 0-1) made the Jayhawks work to the very last minute.

The Cyclones followed a late touchdown by recovering an onside kick with 1:13 left and took over at their own 41. But the Jayhawks defense clamped down, forcing Iowa State's Austen Arnaud to throw four straight incompletions.

Arnaud set career highs with 268 yards passing and three touchdowns, and Iowa State blew a golden opportunity for its first win over a ranked team since 2005.

Kansas flexed its big-play muscle in the third quarter, scoring touchdowns on three straight possessions to move ahead 21-20.

The Jayhawks entered halftime facing its biggest deficit of the season. But Mangino's words proved prophetic, because the Jayhawks were a different team in the second half.

"It was atrocious. It wasn't all our fault. They played very well," Reesing said.

Kansas 35, Iowa State 33

Kansas 0 0 21 14--35

Iowa St. 14 6 0 13--33

First Quarter

ISU -- Robinson 16 run (Mahoney kick), 10:45.

ISU -- Hamilton 8 pass from Arnaud (Mahoney kick), 3:56.

Second Quarter

ISU -- FG Mahoney 31, 12:25.

ISU -- FG Mahoney 43, 8:53.

Third Quarter

Kan -- Sharp 67 pass from Reesing (Branstetter kick), 12:20.

Kan -- Quigley 1 run (Branstetter kick), 8:14.

Kan -- Meier 23 pass from Reesing (Branstetter kick), 1:46.

Fourth Quarter

Kan -- Sharp 2 run (Branstetter kick), 9:23.

ISU -- Sumrall 22 pass from Arnaud (pass failed), 7:33.

Kan -- Meier 21 pass from Reesing (Branstetter kick), 3:39.

ISU -- Hamilton 2 pass from Arnaud (Mahoney kick), 1:15.

A -- 47,847.

Kan ISU

First downs 19 20

Rushes-yards 39-117 31-97

Passing 319 268

Comp-Att-Int 18-26-1 27-46-1

Return Yards 30 15

Punts-Avg. 4-42.0 6-36.5

Fumbles-Lost 4-3 1-1

Penalties-Yards 3-26 4-25

Time of Possession 27:11 32:49

INDIVIDUAL STATISTICS

RUSHING -- Kansas, Sharp 19-79, Reesing 11-20, Quigley 4-13, Crawford 3-8, Team 2-(minus 3). Iowa St., Robinson 10-51, Arnaud 17-44, Darks 1-5, Bass 3-(minus 3).

PASSING -- Kansas, Reesing 18-26-1-319. Iowa St., Arnaud 27-45-1-268, Robinson 0-1-0-0.

RECEIVING -- Kansas, Meier 7-125, Sharp 3-107, Fields 2-56, Briscoe 2-22, Quigley 2-2, Biere 1-10, Crawford 1-(minus 3). Iowa St., Sumrall 10-106, Darks 6-84, Hamilton 3-33, Jones 3-21, Se.Johnson 2-17, Robinson 1-8, Zitek 1-5, Bass 1-(minus 6).