West Indies v England: Tredwell shines before top-order problems
England are in a very good position to beat the West Indies in Antigua and claim their first overseas Test win since 2012 in Kolkata.
With a 220-run lead and seven second-innings wickets still in hand, they are firmly in the box seat, and if they can get through the first hour tomorrow with no mistakes, they can aim to declare just before tea on day four and give themselves a great chance of bowling the West Indies out for victory.
The star performer of the day for England was off-spinner James Tredwell. Tredwell isn't a flashy sort of bowler, and last year he couldn't even get in Kent's four-day team, but he bowled beautifully here to claim four wickets.
It was a first-class display of old-fashioned off-spin bowling: he tossed the ball up and varied his pace subtly. His dismissal of the dogged Shivnarine Chanderpaul was a particularly fine piece of classical spin-bowling: setting the batsman up against a cleverly-set field.
He's given the England selectors a real headache ahead of the second Test in Grenada next week. Moeen Ali, England's first-choice Test spinner last summer, has been added to the squad, but it won't be a question of Tredwell just stepping aside - he's put himself right in contention for selection.
The seamers also bowled well, in particular Stuart Broad. He got himself revved up and bowled with genuine pace and hostility, which is exactly the right way to get back in rhythm when you've been struggling.
However, there are still question marks hanging over the batting. At the moment there is a serious problem brewing at the top of the order.
Captain Alastair Cook has now gone 33 innings without a Test century and the pressure will continue to grow on him after another cheap dismissal, caught at gully for 13.
I actually thought he was shaping up pretty well today - his footwork looked good, his bat was straight, but the shot he got out to was poor.
His partner Jonathan Trott, playing in his first Test series since leaving the 2013/14 Ashes tour with stress-related problems, is also under big pressure after two failures in this match.
Trott has been a magnificent servant for England, but at the moment he has a significant technical flaw, in that he's trying to play towards mid-on, which is a recipe for disaster against the swinging ball.
The selectors have a big call to make on Trott. Do they really see him opening the batting against Australia in Cardiff this summer? If not, they need to seriously consider the claims of Yorkshire's Adam Lyth for the next Test match.
One big positive from England's batting today was the return to form of Gary Ballance after a lean patch. He showed again what a calm young player he is, and if he can get his head down tomorrow, he has every chance of scoring his fourth Test century.
Jonathan Agnew was speaking to BBC Sport's James Gheerbrant.