In 1987, Ian became the first British player to win the World Matchplay Championship at Wentworth. He beat Nick Faldo (quarter-finals), Seve Ballesteros (semi-finals) and Sandy Lyle (final). All three 36-hole matches were won by the margin of 1 up. He also won the title in 1990. Ian Topped the European Order of Merit in both 1987 and 1990.

In 1991, Ian held his nerve superbly to hold off the challenge of Tom Watson and Jose-Maria Olazabal to win the US Masters. With one hole left to play, all three were tied for the lead at 11 under par. Olazabal, playing one group ahead of Watson and Woosnam, bogied the par-4 72nd hole after finding sand with both his drive and second shot. Watson drove into the trees down the right and took six (double-bogey), while Woosnam bravely got down in two for par from just off the putting surface to pip Olazabal by one stroke.

Ian was ranked number one in the world at the end of 1991 - his big year.

Woosnam was a small but powerful player.