I'm working on foot faults, says four-wicket Tahir

South African leg-spinner Imran Tahir enjoyed a four-wicket debut on Thursday, but his World Cup bow was almost shattered by a double warning for running on the pitch.

The 31-year-old Pakistan-born player helped send West Indies crashing to 222 all out in 47.3 overs in their Group B match at the Feroz Shah Kotla stadium with figures of 4-41.

But Australian umpire Simon Taufel twice warned him about straying onto the pitch. A third warning would have seen him pulled out of the attack.

"I'm not comfortable bowling away from the stumps, but I'm working hard on it," said Tahir

"I want to get it right. I don't want to get a third warning and not be able to bowl."

Tahir, who was born in Lahore and has married a South African girl, dismissed Devon Smith, Ramnaresh Sarwan, Devon Thomas and Shivnarine Chanderpaul in his 10-over spell.

He praised the support shown to him by skipper Graeme Smith.

"Graeme had a lot of confidence in me. I bowled well in the second spell, some days you have a bad day, some day a good on, today was a good day," he said.

"In the powerplays, varying the pace is the key."