Intro:

Karlovic into last four after beating Berdych in three sets

Federer, Nishikori, Seppi join Karlovic in semis of Gerry Weber Open.

Script:

It was quarter-final time at the Gerry Weber Open in Halle and Ivo Karlovic kicked off proceedings against third-seed Tomas Berdych. 

The upset was on the cards right from the first set, as Karlovic secured it 7-5. 

The Croat was in spectacular serving form and by the end of the match had beaten his own record for number of aces in best-of-three-set matches. 

He smashed 45 aces in the upset, winning 7-5, 6-7, 6-3 to progress. 

His reward will be a semi-final encounter with Roger Federer. 

This after the top-seeded Swiss made light work of Germany Florian Mayer winning 6-0, 7-6 as he edges closer to a record eighth title in Halle. 

Meanwhile, second seed Kei Nishikori overcame Poland's Jerzy Janowicz in a hard fought encounter. 

The match last two and a half hours with Nishikori eventually prevailing 6-4. 5-7, 6-3 to secure his spot in the last four. 

There he will meet the tournament's surprise package in Italy's Andreas Seppi. 

He was up against France's Gael Monfils, and secured the first set with ease 6-1. 

In the second the fourth seed suffered a right knee injury and was forced to retire, Seppi going through to semi-finals.