There were 19 spectators and 22 stewards dotted around the vast stands of the SWALEC Stadium when play finally got under way 90 minutes after lunch but neither the sparse attendance nor the bleak weather deflected Gareth Rees and David Hemp from their sense of purpose as they put Glamorgan in command with a second-wicket partnership of 154 runs in 36 overs.

Rees, 23, is an adventurous, left-handed opening batsman who was good enough to play rugby for Wales Under-17 before attaining a first in maths and physics at Bath University and is trying to establish himself as a county cricketer.

He hits the ball hard, as Vanburn Holder, the square-leg umpire, will testify after taking a full-blooded pull on the chest, and he went nervelessly through the nineties with a reverse sweep and a clip through midwicket off Nayan Doshi, to complete his third championship century off 132 balls with 13 fours.

Rees was within five runs of his career-best 109 - also against Derbyshire at Cardiff last August - when he was leg-before to the off spin of Jake Needham, but there was no respite for Derbyshire's bowlers as Michael Powell joined Hemp in another punishing stand of 97 runs in 21 overs.

Powell, happily restored to health after fearing that he would never play again last season following complications from a blood clot underneath his collarbone, played some magnificent shots, the best of them a sumptuous cover drive, on his way to 48 off 72 balls with eight fours.

He was then caught at slip when Needham, the best of the Derbyshire bowlers, made one bounce but there was no stopping Hemp as he moved elegantly to his first championship century since September, 2006.

It came off 164 balls with a six and 13 fours and when bad light stopped play soon afterwards he was still unbeaten on 103. That meant that he had scored 374 first-class runs, including two hundreds and two fifties, this season at an average of 124.

Scoreboard

Derbyshire: First Innings 289
(J L Clare 70 not out, C J L Rogers 69; R D B Croft 4 for 93)

Glamorgan: First Innings (overnight 87-1)

G P Rees lbw b Needham 104

*D L Hemp not out 103

M J Powell c Stubbings b Needham 48

J W M Dalrymple not out 6

Extras (b 10, lb 7, w 1, nb 6) 24

Total (3 wkts, 69 overs) 301

M A Wallace, A G Wharf, R D B Croft, J N Gillespie, J A R Harris and D S Harrison to bat.

Fall of wickets: 1-39, 2-193, 3-288.

Bowling: Wagg 14-1-62-1; Langeveldt 16-2-78-0; Clare 11-1-32-0; Doshi 12-0-68-0; Needham 16-3-44-2.

Umpires: V A Holder and R K Illingworth.