Sussex cricket manager Mark Robinson admits he is running out of superlatives for his Pakistani bowling aces.

Mushtaq Ahmed took 5-24 and Rana Naved 4-28 at the Riverside yesterday as first division leaders Sussex hustled out Durham for 110 on the opening day of the Championship match. By the close Sussex were already in front on 119-2.

Between them, Rana (28) and Mushtaq (27) have already taken 55 wickets this season to help Sussex enjoy their best start since 1960.

Robinson said: "They are so good because they bowl as a pair and seem to bounce off each other.

"Mushtaq was superb. He had to bowl into a really strong wind but the control he got as well as the wickets he took enabled us to keep up the pressure at the other end.

"We took wickets regularly and basically that meant Durham had nowhere to go."

Robinson concedes that Rana will be almost irreplaceable when he joins up with Pakistan for their tour of England next month.

He will not be required to attend a pre-tour camp in Lahore which starts tomorrow and Sussex are still hopeful he will be available for three more Championship games, although this will not be confirmed until after the squad is finalised on June 9.

Robinson said: "It is going to be hard for whoever takes over from Rana because inevitably they will be compared.

"But we could bring in any world-class bowler - Brett Lee, Glenn McGrath or whoever - and he would struggle to produce what Rana has done for us."