Henin got directly in the top 100 by winning her debut tourney in Antwerp '99 where she got a wildcard. Despite that she had to go through quallies to get to RG, where she fell to Davenport in the second round in a very close match.
Also an amazing feat: Clijsters was still 15 when during that same tournament in Antwerp she a got a WC for the quallies. She qualified and got through to the QF where she squandered (!) a matchpoint against Pitkowski.
That gave her just enough WTA points to be admitted as the last qualifier at Wimbledon '99. She won six matches in a row there and got straight to the top 100 before falling to Graf. The world press was whining about Dokic there but I knew better at the time.