Berdych downs Monfils to win Montpellier
World number seven Berdych had too much pace for Frenchman Monfils and prevailed in two hours five minutes.
"It was a great three sets, it was very close and I'm happy I was able to do it," top seed Berdych told French TV channel Canal Plus Sport.
"He is a great player, he knows how to fight on court, but I knew that and I was ready for it."
Monfils, who was the defending champion, admitted the better player had won.
"I tried to return his serves better, to be more aggressive but it is not easy when he steps on to the court," he said.
Berdych took the first set easily but world number 13 Montfils started to move much better in the second.
He opened up a 3-1 lead and although the Czech threatened to level in the eighth game, Monfils held serve to send the match into a decider.
Monfils saw off two break points in the eighth game but conceded the third to let Berdych serve for the match.
The Czech duly delivered, wrapping it up on his first match point with a backhand winner.