Top seed John Isner is just one match away from advancing to his fifth finals appearance at the BB&T Atlanta Open. Standing in his way is Denis Kudla who is the first qualifier to make the semifinals in the six year history of the Atlanta Open.

(1)John Isner vs. (Q) Denis Kudla

Isner was thumping aces all over again in his quarterfinal win over Ricardas Berankis 7-6 (5), 6-4. Isner hit 19 aces in all and seemed in rhythm for just about the entire match. He did offer up a couple of break points in the second set, but erased them easily. He won 80 percent of his service points on Thursday. Berankis wasn't bad in his own right, winning 77 percent of his serve points.

The only real difference between the two came on a point in the first set tie break and a single loose service game in the second. The problem is that is what John Isner does. He puts pressure on your service games constantly when he is in that rhythm on-serve. It goes into a player's head before the match even begins, "I have to hold serve every time or else". By making the quarterfinal a relatively quick match in one hour and 20 minutes, Isner also should have plenty left in reserve.

Kudla once again had some issues in the first set of a match, but was able to persevere for a relatively simple win in the end on Thursday. He started extremely well against Dudi Sela as Kudla broke Sela in his opening service game for a quick 2-0 lead. Kudla would secure a second break that left him up 5-1 late in the set. That's when things went off course for the America.

Kudla was broken trying to serve the set out and then broken yet again as Sela rallied back to even the set at 5-5. Kudla steadied himself to hold to a 6-5 lead and then would get a decisive break for a 7-5 set win. Kudla's second serve was a big culprit in his mini-meltdown as he won just three of 12 points on his second serve in the opening set.

It was shades of his second round match against Jack Sock. And much like the Sock match, Kudla would turn things around quickly as his opponent appeared to wilt in the heat either physically or mentally. Kudla served up a bagel in the second set to defeat Sela 7-5, 6-0. Sela was wretched, winning just eight of 22 points on his own serve in the second set.

For the match, he won just 48 percent of his service points. You can say Kudla might have benefitted from a pair of lackluster efforts the past two days, but the bottom line is that he mentally stayed in these matches while his opponents seemed to go away. That's a big thing moving forward to his first ever ATP-level semifinal.

Beast vs. The Beauty

This columnist won't mince words. Watching a John Isner match often has you flipping couch cushions to find your remote to change the channel. There is nothing especially pleasing to the eye about watching him whomp down a ton of aces in a match. Sure, there's the wow factor of watching the radar light up with MPHs touching 140 plus at times.

As far as riveting tennis though, you should seek other matches than a John Isner match. Aesthetically, his game is beast-like. He's going to pound on unwilling participants with a huge serve over and over. He's going to keep any rallies short and sweet in an effort to conserve energy. That is what makes him the King of Atlanta.

Kudla meanwhile will give you some more aesthetically pleasing characteristics to his game. Solid and compact ground strokes from the baseline and mostly good defending in rallies. He isn't going to hit a 140 MPH serve. He's going to try and hit his spots and likely focus on getting his serves to the backhand return of Isner that is definitely the weaker of the two sides. There is some charm to that part of his game whereas Isner is mainly going to give you the heater and bank on you not being able to return it well enough over the course of the match to beat him.

The beast is effective though, especially on these courts. Isner's has laced 52 aces onto the hard courts in Atlanta through two matches. He said the conditions on Friday in the heat of the day actually helped his serve gain more speed than he had on it Thursday. That could explain why Isner was broken twice by Radek Stepanek, but was able to tighten that up in the quarterfinals as Berankis failed to break him on just two opportunities. Isner won 84 percent of his first serve points against the Lithuanian and has won 70 percent of his second serve points this week. That sort of number makes him nearly impossible to beat, unless you can sneak past him in a tie break.

That might be Kudla's game plan, but he may also struggle to execute it. His serve has been broken seven times through his three main draw matches on 18 break chances. Kudla has rarely faced servers who hit as big as Isner this season. You could say playing Sock helped prep him for tomorrow, but Sock lacks the consistency of power that Isner brings. Sock can reach those crazy speeds over 140 MPH, but his accuracy normally suffers. Isner? He's like a Cy Young pitcher, painting corners with unhittable heat.

You Got Served

It almost seems an abomination that John Isner wasn't in the cast for the 2004 movie of the same name. After all, he could whip that phrase out almost every match he plays in Atlanta. The King serves the peasants with those filthy and wickedly fast serves up the tee and is an equal opportunity server by crushing those same serves out wide with laser precision.

This match comes down to serve. Yes, there will be some rallies. Isner will have to fire off some forehands and backhands to win this match, but the decisive factor is as almost always with Isner, serving. The question for Kudla is can he keep pace? Can he match the big man service hold for service hold and then maybe get a little luck in a tie break or two?

Kudla has done well this week and certainly can be proud of the arc his career is currently on. As for this semifinal, it will be difficult for him to match Isner serve for serve if Big John is anywhere close to the level he was at on Friday. Look for Kudla to keep the scoreline similar to what Berankis was able to do in the quarterfinals

Prediction: John Isner in two close sets