Chris Rogers made Sussex pay for dropping him twice as he put Middlesex well on top after the first day of their Championship clash at Lord's.
Rogers was dropped when he had made just three by Mike Yardy and then again on 106 as he went on to score an unbeaten 161 and steer Middlesex to 318-3 having been asked to bat.
Sussex skipper Ed Joyce may be rueing his decision to field first as Rogers put on 100 with Sam Robson for the opening wicket before adding a further 123 with Neil Dexter for the fourth wicket.
All three Sussex wickets went to spin with Will Beer the pick of the Sussex bowlers having been selected ahead of Monty Panesar.
Sussex welcomed back Matt Prior from international duty and also handed Chris Liddle and Beer rare starts in the Championship.
Prior replaced Rory Hamilton-Brown while Beer and Liddle came in for Panesar – who has been struggling with a shoulder problem - and James Anyon respectively.
Joyce’s decision to bowl first looked a bold one but it should have paid instant dividends when Yardy dropped Rogers at second slip off the bowling of Steve Magoffin when he had made just three.
That proved a key moment as the Australian opener went on to put on 100 for the first wicket with Robson.
Robson brought up his 50 off 74 balls with eight fours before being trapped lbw by Beer on the stroke of lunch for 54.
Beer picked up his second wicket when he bowled Joe Denly for 11 with a ball that went straight on while Chris Nash struck at the other end to remove Adam London for 18 when he padded up to a straight ball.
But Rogers continued to punish Sussex for that early reprieve as he brought up his 50 off 94 balls and went on to complete his hundred off 167 deliveries by sweeping Beer for four.
The Middlesex skipper received another life when he was put down at slip by Chris Jordan on 105 when he attempted to cut a wide ball from Beer.
Together with Neil Dexter (62 not out) the pair added 123 for the fourth wicket to move Middlesex on to 320-3 at the end of the day with Rogers reaching the close unbeaten on 161.