ANAHEIM, Calif. - Jim Calhoun could scarcely watch when the most improbable postseason run of his coaching life at Connecticut came down to an open 3-point attempt by Arizona's Jamelle Horne.

The shot clanged off the back rim. The clock hit zeros.

Nine victories in just 19 days. Calhoun has seen just about everything, but nothing like this — and now his Huskies will keep running all the way to Houston.

Kemba Walker scored 20 points, freshman Jeremy Lamb added 19 and UConn earned its second Final Four berth in three years, beating Arizona 65-63 Saturday to win the West regional.

After missing the NCAA tournament entirely last year, Calhoun's tireless team is headed to the Huskies' fourth Final Four, punctuated by an ebullient on-court celebration in a building packed with Arizona fans.

UConn simply hasn't lost since a .500 Big East regular season, winning five games in five days at the conference tournament before this NCAA run. Walker claims he isn't surprised by this sprint through the postseason, while Lamb has nothing to compare it to, leaving Calhoun alone in his grateful disbelief.

"Never did I imagine a team winning nine games in tournament play in 19 days," Calhoun said. "These brothers, these young guys, have just given me a thrill beyond compare. Our march in the past nine games, I haven't experienced anything like this."

UConn also made the Final Four in 1999, 2004 and 2009 — all three times out of the West. In sweet redemption for a program and a veteran coach tarred by scandals over the past year, the Huskies will face the winner of North Carolina's East regional final against Kentucky next Saturday.

Derrick Williams and Horne missed go-ahead 3-pointers in the final seconds for Arizona, allowing the third-seeded Huskies (30-9) to hang on after Lamb scored six key points down the stretch when Walker encouraged the Huskies to run plays for the fearless frosh.

"This is no time to be tired," Walker said. "We're trying to get as far as possible. We want to win this whole thing."

Williams had 20 points while battling foul trouble for the fifth-seeded Wildcats (30-8), who led with 6 minutes to play. After Lamb pushed the Huskies ahead and Walker hit a jumper with 1:13 left, Lamont Jones and Horne then hit late 3-pointers for Arizona, but the Wildcats couldn't convert two good looks in the final seconds.

"The second one, I thought it was definitely going in," Lamb said. "When he missed it, I looked at the clock and saw zero-zero, and I just went, 'Whooooo.' It's the best feeling I've ever had."

The Huskies are the last team standing from the Big East's 11 NCAA entrants. After going 9-9 in regular-season conference play, they've done more than even Calhoun might have expected just three weeks ago.

After the Wildcats missed their final two shots, Walker and Calhoun wrapped each other in a bear hug at center court after the buzzer as Emeka Okafor, Jake Voskuhl and other UConn alums celebrated on the court.

The two-time national champion coach has referred to his group as "an old-fashioned team," a praise of their work ethic and resilience. But they also showed remarkable poise down the stretch in a building firmly in favor of the Wildcats.

A year after Arizona's 25-year streak of NCAA tournament appearances ended, the Wildcats and second-year coach Sean Miller were one 3-pointer away from a return to the Final Four. Williams demolished Duke in the regional semifinals with a career-high 32 points, but three early fouls limited him to 7 minutes in the first half against UConn.

"I've never been prouder of a team, and I've never seen a team come so far as we did in a short period of time," Miller said. "It will probably feel better in a few weeks than it does now."

Jesse Perry scored 14 points for Arizona, which trailed 34-25 early in the second half before scoring nine straight points. The Wildcats reclaimed the lead with 14½ minutes left on Williams' layup, but UConn quickly scored seven consecutive points.

The Huskies led 50-41 until the Wildcats made a 12-2 run that included two rim-ripping dunks by Williams and the go-ahead slam by Perry with 7:17 left. With Honda Center rocking in Arizona red, Lamb smoothly put the Huskies ahead before following Alex Oriakhi's putback layup with a steal and a dunk with 3:08 left for a seven-point lead.

UConn just keeps rolling in what has shaped up as a magnificent season after last year's disappointing NIT trip. The Huskies roared through the league tournament with an unprecedented display of endurance at Madison Square Garden.

"I only feel tired after everything is over," Walker said. "When I'm playing, it's no problem. I'm good."

Walker kept up his incredible scoring pace in the tournament, dropping 33 points on Cincinnati before equaling the highest-scoring tourney game in UConn history with 36 against San Diego State in the regional semis.

Jones did a fairly decent job slowing Walker, his good friend since the sixth grade in New York City. They played together for two years at Harlem's Rice High School, although Walker claimed their history wouldn't give Jones an advantage in their first head-to-head meeting since their AAU days.

Good thing Walker had Lamb, the lanky shooter who betrayed no inkling of nerves in the biggest game of his life.

"I definitely expected to play in the NCAA tournament and have a chance at the Final Four when I chose UConn," Lamb said. "I just didn't know it would happen this fast."

Arizona won the Pac-10 regular-season title and made the top 10 for the first time in late February, but lost consecutive league games in Los Angeles before dropping the Pac-10 tourney finale to Washington on a buzzer-beater.

Last week, Arizona knocked off powerful Memphis and Texas before their 93-77 victory over the Blue Devils.

The West Coast crowd was solidly behind Arizona, with red-and-blue fans filling most of the lower bowl. Williams and the Wildcats repeatedly waved their arms before UConn's possessions, riling up the noisy crowd.

"For us to be one of the last teams standing, a lot of people want to be in our shoes," Jones said. "It's unfortunate that it has to end here, but the feeling of playing here is something you'll always remember."