Complex sentence: The race was again a disappointment for Leslie who led from pole but retired with a mechanical problem, giving the lead to Winkelhock who had done a great start from 6th to lead by the 1st corner.
Split into simpler sentences: The race was again a disappointment for Leslie, who led from pole, but retired with a mechanical problem. This gave the lead to Winkelhock, who had a great start from 6th to lead by the 1st corner.