Williams boss praises Button

The 20-year-old is under extreme pressure to do well in Monaco as he has less than a handful of races to save his seat from the clutches of last Sunday's Indy 500 winner Juan Pablo Montoya.

Button was an impressive eighth fastest in the first session of the weekend headed by four-time winner Michael Schumacher.

Team-mate Ralf Schumacher was at the bottom of the times after clouting the barrier at Portier on his fourth lap and ending up last of the 22 runners in the first session.

"Jenson's done a very good job and had an exceptional practice," said Head.

"He has been going well and if it had not been for a car going into the barriers and halting the session he was on a lap that would have put him third or fourth."

Head is looking forward to the challenge of Monaco where his team - currently third in the table - could reasonably expect to battle hard with the Ferrari's and the McLarens for a podium place.

"It's a different race to the others, but its a great challenge and it gives you great satisfaction if you get it right," added Head.