Sam Robson completed a third century of the season to put Middlesex in a strong position against LV= County Championship leaders Sussex.
The 24-year-old Sydney-born opener made 166 as Middlesex ended the second day at the BrightonandHoveJobs.com County Ground on 445 for five in response to Sussex's 229, leading by 216.
A bone-dry pitch continued to offer plenty of assistance to the seamers, with good carry and occasional steepling bounce.
While Middlesex enjoyed a fair share of good fortune, their batsmen were much more selective than those of Sussex when going on the attack.
Robson has now scored 979 first-class runs and 968 in the championship. He figured in punishing stands of 120 and 102 with Joe Denly and skipper Neil Dexter respectively to leave Sussex in danger of their first defeat of the season.
Middlesex will also be able to call on Steven Finn when Sussex bat again after he was left out of England's Test team against Australia.
It was a gruelling day for the home attack in stifling heat, although Australian Steve Magoffin took two more wickets and now only needs three to become the first bowler to reach 50 for the season.
Middlesex built a solid platform by scoring 120 runs in the morning session for the loss of just one wicket. That came when Dawid Malan, on 30, edged a lifting delivery from James Anyon behind.
In contrast to Robson, Denly has been in poor form and he made the most of a let-off on 31 when he was put down by Chris Nash at short-leg off Magoffin.
Denly went on to score 87, his highest score of the season, with 12 fours and a top-edged six off Chris Jordan, He was eventually caught at short midwicket off the third ball after lunch to reward the persevering Magoffin.
Anyon returned to the attack to have Adam Voges caught at short cover off a top-edged pull, but Middlesex soon regained the initiative.
Dexter had moved to 48 when Magoffin took the new ball and knocked back his off stump, while Robson continued to look in supreme form, both against the seamers and Monty Panesar.
The left-arm spinner was economical but struggled to make any inroads before Robson, having just lofted him over the long-on boundary for six, came down the pitch looking to repeat the shot and was bowled by a delivery which kept very low. His 261-ball knock lasted more than six hours and featured 23 boundaries.
Gareth Berg was dropped on nine when Nash appeared to lose sight of the ball in the sun as he ran in from the square-leg boundary. By stumps, Berg and John Simpson had put on 51 for the seventh wicket.