UPDATE 2-Tennis-Djokovic labours past Rochus into Halle final

* Djokovic beats qualifier Rochus to reach final

* Serb faces Germany's Haas in Sunday's showdown

(adds Djokovic quotes)

By Karolos Grohmann

HALLE, Germany, June 13 (Reuters) - Novak Djokovic had to work hard against Belgian qualifier Olivier Rochus to reach the Halle tournament final with a 7-6 6-4 win on Saturday.

The Serbian world number four will play Germany's Tommy Haas who earlier beat Philipp Kohlschreiber in three sets.

Djokovic, who has struggled to find his feet on grass all week, squandered a 4-1 lead and then missed three set points at 5-4 before Rochus carved out two for himself in the tiebreak.

Second seed Djokovic, who littered the court with 21 unforced errors in the first set alone, kept his composure to clinch it on his fourth set point when the 136th-ranked Rochus sent a backhand sailing wide.