Alex Hepburn scored his second hundred for Worcestershire Seconds on the opening day of the four-day encounter with Middlesex at New Road.
Hepburn and George Rhodes were largely responsible for Worcestershire totalling 306 all out after winning the toss.
Then skipper Joe Leach picked up two wickets to reduce Middlesex to 35-2 by the close.
Rhodes continued his fine form so far this season by making 76 in four hours off 180 balls with one six and eight fours.
He shared in partnerships of 59 with Leach (35) and Hepburn (89) before being sixth out at 208.
Worcestershire then slumped to 231-9 but Hepburn displayed some remarkable hitting to push the total past 300.
His first 50 came off 128 balls and his second 50 from just 22 deliveries with five fours and five sixes in that second 50.
Hepburn scored 73 of the 75 added in eight overs in a last wicket partnership with Adil Rashid who finished two not out.
He was finally dismissed for 113 made off 163 balls with six sixes and 13 fours.
Hepburn's other Seconds hundred came against MCC Young Cricketers at High Wycombe in a Second Eleven Trophy match in 2013.
Leach trapped Middlesex opener Ryan Higgins lbw for 16 and in his next over had Ravi Patel caught behind by Joe Clarke for nought.
Worcestershire 2nd XI (1st Innings)
JM Clarke+ c and b HW Podmore 10
BL D'Oliveira c SS Eskinazi b HW Podmore 17
GH Rhodes lbw b GS Sandhu 76
RA Whiteley c RF Higgins b D Childs 16
J Leach* c SS Eskinazi b GS Sandhu 35
EG Barnard c PR Stirling b GS Sandhu 0
A Hepburn b RH Patel 113
AJ Hose lbw b GS Sandhu 0
CJ Russell b GS Sandhu 4
JJ Dilley lbw b OP Rayner 2
A Rashid not out 2
Total 306 all out
FOW: 26, 35, 60, 119, 119, 208, 212, 216, 231, 306.
Bowling: Podmore 2-52, Sandhu 5-60, Childs 1-36, Rayner 1-65, Patel 1-10
Middlesex 2nd X1 (first innings)
SS Eskinazi not out 14
RF Higgins lbw Leach 16
RH Patel c Clarke b Leach 0
A Balbirnie not out 3
Total (for 2 wickets) 35
FOW: 30, 32.