Derbyshire are on course to end their long wait for a home victory in the County Championship after they completely dominated the second day of the Division Two match against Middlesex at Derby.
Middlesex were shot out for 157 with South African fast bowler Duanne Olivier taking 4 for 26 on his Derbyshire debut and despite a two hour break for rain, the home side closed on 118 without loss to lead by 226 runs.
The visitors attack was again weakened by the absence of England seamer Toby Roland-Jones who has a sore back and Derbyshire will go into the last two days confident of wrapping up a first home win since September 2014.
They seized the initiative from the moment Middlesex captain Sam Robson fell to the first ball of the second over of another sunny morning when Ravi Rampaul trapped him lbw for 19.
Robson had batted for 122 minutes so to get him early was a big boost and they picked up nightwatchman Ollie Rayner in the next over when he was pinned by a full length ball from Hardus Viljoen.
John Simpson played a typically combative innings and with Paul Stirling was rebuilding the reply until they both fell in the space of two overs.
Simpson was looking dangerous but on 32 he left a ball that swung in to take the off stump and Stirling was lbw to Tony Palladino in the next over to reduce the visitors to 124 for 7.
Olivier swept away the tail after lunch by having Tom Helm smartly caught low down at first slip by Wayne Madsen and trapping James Harris in front with one that came back to give Derbyshire a significant first innings lead of 108.
Middlesex needed quick wickets to stay in the game but although Luis Reece survived a sharp chance to second slip off Helm just before the rain arrived with Derbyshire 56 from 21 overs, the Derbyshire openers played with increasing authority after the skies cleared.
Slater completed his 50 from 73 balls when he cut Helm for his seventh four and was unbeaten on 63 with Reece not out 47 at the end of a highly satisfactory and encouraging day for Derbyshire.