Back to his best: Stephen Harmison pounded his way to 100 Test wickets © Getty Images

There have been very few worries as England have blown away West Indies this summer. But one slight question-mark had been the form of Stephen Harmison, who had seemed a little jaded in this series, in which he had taken only eight wickets at a costly 47.62. Before today.

That's all changed now. Harmison warmed up with a breezy Test-best of 36 not out, with three sixes, including one that zinged into the stands over long-on which John Daly would have been proud of. And then Harmison bobbed in to bowl. For the first time for a few weeks everything looked right, as those coathanger shoulders heaved up and down, and propelled the ball down the pitch at great velocity - terminal velocity, indeed, for the West Indian batsmen.

He worked out the openers, Chris Gayle and Sylvester Joseph, then took a breather. Later he bounced out Dwayne Bravo, and was altogether too much for Carlton Baugh - who guided a slip catch as if giving pre-match practice - and Corey Collymore, who edged a screamer into the slips, where England were faultless all day. And then came the big one, as Brian Lara, looking to retain the strike, toe-ended a pull down to the debutant Ian Bell.

Harmison finished with 6 for 46, out of only eight wickets to fall to the bowlers (Fidel Edwards was run out by Matthew Hoggard's pinpoint throw, and Dwayne Smith was injured). That took him to 99 Test wickets: No. 100 eluded him for a while, but he returned for a final spell and reached three figures when Joseph flinched one through to Geraint Jones. He's the 37th bowler to take 100 Test wickets for England - and one of the quickest, both in terms of mph (90-plus) and matches required (23).

It hadn't exactly been a long lapse of form - Harmison finished top of the averages against New Zealand earlier in the summer, with 21 wickets at 22.09 - more a slightly worrying blip. But today proved the truth of that popular T-shirt slogan: form is temporary, class is permanent. And Steve Harmison's bowling is very classy indeed just now.

Steven Lynch is editor of Wisden Cricinfo.