BOULDER, Colo. โ€“ Returning from injury, Khalil Tate passed for a career-high 404 yards to lead the Arizona Wildcats to a 35-30 victory at Colorado on Saturday at Folsom Field.

Tate, who missed last weekโ€™s game against UCLA, also threw three touchdown passes. Nathan Tilford ran for two scores, including the go-ahead touchdown with 6:51 left in the fourth quarter.

Arizona won its fourth in a row to improve to 4-1, 2-0 in the Pac-12. Colorado fell to 3-2, 1-1. The Wildcats have sole possession of first place in the Pac-12 South.

A back-and-forth game boiled down to one play. Colorado needed to convert on fourth-and-5 from the UA 47-yard line late in the fourth quarter. A blitzing Tony Fields II got pressure on CU quarterback Steven Montez, whose pass sailed over the head of intended receiver Dimitri Stanley. Tristan Cooper had tight coverage on the play.

Arizona trailed 20-14 at halftime. The Wildcats needed just one possession to erase the deficit.

Arizona running back Darrius Smith, center, is dragged down after a short gain by Colorado defensive end Terrance Lang, left, and linebacker Carson Wells in the first half of an NCAA college football game Saturday, Oct. 5, 2019, in Boulder, Colo. (AP Photo/David Zalubowski)

Arizona drove 65 yards in six plays, all of them passes. Tate finished the drive with a 33-yard pass to Brian Casteel. It was the first career touchdown for Casteel, who had a rough first half.

After four consecutive punts, the Buffaloes reclaimed the lead. Steven Montez connected with Tony Brown for a 49-yard pass to the UA 18. On the next play, Brown took the ball on an end-around and maneuvered through the Arizona defense for a touchdown. That put Colorado up 27-21 with 5:11 left in the third quarter.

Again, the lead didnโ€™t last long. Arizona needed just six plays and 1 minute, 29 seconds to go 85 yards via a mix of play-action passes and runs. Nathan Tilford finished the drive with a 5-yard TD plunge to give Arizona a 28-27 lead.

As was the case for much of the first half, Arizonaโ€™s defense bent but didnโ€™t break on the next possession. Colorado had first-and-goal at the 2, but back-to-back tackles for losses stunted the drive. James Stefanouโ€™s third field goal, from 20 yards, put Colorado up 30-28 with 11:29 left in the fourth quarter.

The Wildcats again responded, this time putting together a 13-play, 77-yard TD drive. Tilfordโ€™s second touchdown, again from 5 yards out, put Arizona on top for good.

HALFTIME UPDATE:

BOULDER, Colo. โ€“ With Khalil Tate back in the lineup, the Arizona Wildcats trail Colorado 20-14 at halftime of their game Saturday afternoon at Folsom Field.

Tate returned after missing last weekโ€™s game against UCLA because of hamstring and ankle injuries. He has completed 8 of 14 passes for 175 yards with two touchdowns and one interception.

The interception was costly. While rolling to his right late in the second quarter, Tate forced the ball over the middle. Mikial Onu picked it off and returned it to the UA 38.

On the next play, receiver K.D. Nixon took the ball on a reverse. But he didnโ€™t keep it. Nixon fired a pass to a wide-open Dimitri Stanley in the end zone for a touchdown. The 38-yard TD gave Colorado a 13-7 advantage.

It didnโ€™t last long. On the next play from scrimmage, Tate connected with Cedric Peterson for a 75-yard score. Just like that, Arizona was back on top 14-13.

The Wildcats couldnโ€™t hold the lead. The Buffs marched 75 yards in nine plays. Steven Montez completed the drive with a scrambling 12-yard TD pass to Brady Russell with three second left in the half.

Jamarye Joiner nearly returned the ensuing kickoff for a touchdown, but he stepped out of bounds at the CU 46.

Mental errors on special teams hurt the Wildcats in the first half. Brian Casteel twice fielded punts at or inside the 10-yard line. The second of those forced Arizona to start from its 4. The offense went three-and-out, and Colorado started the next drive at the UA 49.

As it did throughout the half, Arizonaโ€™s defense held. Colorado had to settle for a field goal. James Stefanouโ€™s second field goal of the half cut Arizonaโ€™s lead to 7-6.

Arizonaโ€™s average starting field position in the first half was its 21. Coloradoโ€™s was its 35.

Colorado started with the ball and drove deep into Arizona territory, advancing to the 12-yard line. But Anthony Pandy tackled Alex Fontenot for an 8-yard loss on second-and-3. Christian Roland-Wallace then broke up a pass from an under-pressure Montez on third-and-11. Stefanouโ€™s 37-yard field goal gave the Buffaloes a 3-0 lead.

After a pair of punts, Arizonaโ€™s offense finally got rolling. Tateโ€™s 7-yard TD pass to Stanley Berryhill III gave the Wildcats a 7-3 lead. Earlier in the drive, Tate connected with Peterson for 16 yards on third-and-6 from the UA 14. Two plays later, he hit Tayvian Cunningham on a slant for 49 yards.

Tateโ€™s TD pass was the 50th of his career, moving him into third place on Arizonaโ€™s all-time list.

Although he dressed and participated in warmups, Colorado receiver Laviska Shenault was declared out because of a core-muscle injury.

Arizona tailback J.J. Taylor started, carried the ball on the Wildcatsโ€™ first play but spent the rest of the half on the sideline. Taylor sat out last week because of an ankle injury.

Check out photos from Saturday's win here:ย 

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Contact sports reporter Michael Lev at 573-4148 or mlev@tucson.com. On Twitter @michaeljlev