KANSAS CITY, Mo. -- Last weekend, Kansas successfully avoided losing to a 16 seed, then successfully mounted a furious second-half rally to blow away North Carolina and survive to the NCAA tournament's second weekend despite an eventful two games.

It wasn't difficult to spot who was most responsible for the Jayhawks' fate: He was the tallest man on the floor, and he provided a couple lasting images from the Jayhawks' weekend at the Sprint Center.

a) A couple minutes into the second half, Kansas sprung to life against North Carolina after a dreadful first 20 minutes. After hitting Kansas' first three-pointer of the tournament, Travis Releford steals the ball, dribbles nearly the length of the court, then pitches back to a trailing Jeff Withey, who takes off about halfway into the paint, kind of glides toward the basket and slams it through with his one hand as P.J. Hairston duck out of the way to avoid becoming Brandon Knight Part II.

b) With less than two minutes left and Kansas in control up by 13, Withey puts the exclamation point on the evening. Already with four blocks to his credit, the seven-foot senior decides to leave his post in front of the basket, wanders out to defend the perimeter, where UNC's Reggie Bullock attempts a long three-pointer, only to have Withey reach out and swat it away before it gets anywhere -- and catch it himself, for good measure. To make things even worse for North Carolina, CBS cuts to a Tar Heel fan who, um, got a little emotional (0:30 mark below) after Withey put an end to the proceedings.

The cliché says that good guard play is essential to success in the NCAA tournament. Perhaps that's true: Consistently hit shots from the outside and avoid turnovers, and you will, obviously, have a good chance of advancing.

But good guard play is possible to find anywhere. The rarest commodity in college basketball is the seven-footer who can dictate the flow of the game on both ends of the court, and Kansas is fortunate enough to have one.

"If we could find the 6-10 guy that has speed, quickness, energy and can shoot threes, we'll take him," VCU coach Shaka Smart said at the Atlantic 10 tournament, explaining his undersized roster and speaking for most of college basketball's non-powers. "If you've seen one, let me know. The problem is Kentucky and North Carolina want those guys too."

Withey does not exactly fit Smart's template. But he is seven feet tall, one of only six seven-footers remaining in the Sweet 16, one of only three who are significant contributors, one of only two stars and the only one who ranks in the top 100 nationally in blocked shots. Plus, as a former beach volleyball player, he has unparalleled timing and anticipation as a shot blocker with superior movement skills for a player his size.

Indiana's Cody Zeller may be the most talented center left in the tournament, the one with most NBA upside, and Duke's Mason Plumlee, Louisville's Gorgui Dieng and Florida's Patric Young are big-time talents underneath as well, but an aggressive Withey on both ends of the floor can alter a game like no other center in college basketball.

"The first half I went really soft, and Coach [Bill] Self came in at halftime and said we have a size advantage but we're not using it," Withey said after Sunday's game. "I knew that I had to just go through everybody and dunk it. That's what pretty much happened in the second half. I just knew that I had to go stronger, and I knew the refs were letting us play, and so I wasn't going to let anything go."

The first half had seen the refs let things go, including an accidental elbow to Withey's eye by North Carolina's James Michael McAdoo that left quite a shiner. ("May get some pity loving for him," Self said with a wide smile afterward. "Somebody might feel sorry for him.") The elbow was about the only thing McAdoo could do to get the best of Withey. He finished the game 5-for-19 from the field and was blocked twice by Withey, who totally controlled the paint against Roy Williams' reluctant smaller lineup, which proves that despite Smart's statement even North Carolina can't always have a dominant center.

It was, of course, far from the first time Withey controlled an extended area around the rim. Two days earlier, with Western Kentucky threatening to become the first 16 seed to ever beat a top seed, Withey finished with 17 points and seven blocked shots -- posting more blocked shots than the Hilltoppers had made field goals in the first 15 minutes of the second half. After the game, WKU coach Ray Harper bemoaned the fact that his undersized lineup kept attempting to attack the rim, driving to score instead of driving to kick out, making the enormous mistake of thinking they could shoot over Withey.

"Well, the culture out there tells them they're a man when they're six years old and they can go and dunk over a seven-footer," said North Carolina's Roy Williams on Saturday when asked about the Hilltoppers' problem. "… If one of our 6-3 guards gets an offensive rebound and tries to shoot it over Jeff, the next thing you'll see is we'll have another 6-3 assistant."

While star Kansas freshman guard Ben McLemore has disappeared the first two games in the tournament, not making a field goal outside of a foot from the rim, Withey has thrived, overcoming his tentative first-half play on Sunday to finish with 16 points, 16 rebounds, five blocks and two assists. For the second game in a row, he completely disrupted the objectives of the opposing offense, making it easy to see why Kansas owns the nation's best field-goal percentage defense (35.7 percent), why Withey leads the nation in blocks and stands second among all-time shot blockers in the NCAA tournament, seven behind Tim Duncan.

"If you have a shot-blocker around the basket, you take away the other team's second-shot opportunities," Williams said. "If they get an offensive rebound, he has a chance to block it. You have people on the perimeter like Elijah [Johnson] and Travis [Releford], who do a good job defensively and keep the ball in front of them. They have length. They can steal the ball, but they don't think that's necessarily their No. 1 objective.

"Their No. 1 objective is to give you a bad shot."

As the North Carolina game proved, the Jayhawks are as good as anyone in the country at forcing bad shots, ones that may even cause fans to get a little emotional.

Even great guards can make the mistake of driving into a seven-footer and thinking they can shoot over him. Over and over, Withey makes them pay, and it's he who changes the complexion of the game on both ends of the floor as well as anyone left standing in the Sweet 16.