Chris Rogers hit his 60th first-class hundred, and second of the season, to guide Middlesex to 320 for three on the first day of the LV=County Championship Division One match against Sussex at Lord's.
It was a tough day for top-of-the-table Sussex against the side in third, who are the only other unbeaten team in the division, with Rogers finishing on 161 not out and putting on an unbroken 123 for the fourth wicket with Neil Dexter, unbeaten on 62.
Rogers and his opening partner Sam Robson put on 100 after the hosts were surprisingly asked to bat by Ed Joyce, who clearly thought there would be some early help for his seamers on a pitch tinged with green.
Robson made a solid 54 before falling on the stroke of lunch, leg-before on the back foot to 24-year-old leg-spinner Will Beer - who was playing only the third championship match of his career as a replacement for Monty Panesar, ruled out with a shoulder injury.
Rogers was fortunate to be dropped on three, by Michael Yardy going to his left at second slip as the Australian fenced at a ball angled across him by paceman Steve Magoffin.
The 35-year-old, who will join up with Australia's Ashes squad towards the end of June, also had a let-off on 105 when he cut hard at Beer and saw Chris Jordan fail to cling on at slip as he dived to his left.
Rogers otherwise looked in total control as Sussex's quicker bowlers struggled to make an impact on a surface which played far better than might have been expected when Joyce made his decision at the toss.
After tea, Rogers and Dexter made sure it would be Middlesex's day and not even eight overs of the second new ball could break their excellent stand. Both Magoffin and Jordan tried hard to bring Sussex a late breakthrough, but to no avail.
In early afternoon, Joe Denly laboured for his 11, until he was bowled by a faster, skidding delivery from Beer, and Adam London - preferred to the dropped Dawid Malan - batted nicely for 18 before being adjudged lbw to Chris Nash's off-spin.
At the close, Rogers had batted for six hours and eight minutes, facing 279 balls and hitting 18 fours, while Dexter's innings had occupied 115 deliveries, with seven fours.