Sussex 60 for 4 trail Middlesex 230 (Holden 84*, Robinson 7-58) by 170 runs
Sussex seamer Ollie Robinson produced championship best figures of seven for 58 as Middlesex were bowled out for 230 at Hove.
It was the second time this season that Robinson had taken seven wickets in an innings - last month he enjoyed a career-best return of seven for 23 against Loughborough MCC University on the same ground.
But Middlesex hit back when Tim Murtagh took two wickets in successive overs to leave Sussex five for two in the fifth over. And then James Harris also struck twice to leave the match in the balance with Sussex 60 for 4 at the close.
"I trained hard in the winter, playing grade cricket in Sydney, and I feel I have come back fitter and stronger," Robinson said "And the lads say I'm hitting the gloves harder as well, so there might be a bit of extra pace there too. I was injured a lot last season. Now it feels good to have a proper bowling stint and not to have sore legs afterwards."
Middlesex had won the toss before this Specsavers County Championship Division Two match but their batsmen were made to work hard against a spirited attack on a lively pitch. At lunch they were 81 for five before a damage-limiting unbeaten 84 from former England Under-19 captain Max Holden gave their bowlers something to work with in a compelling day's cricket.
Robinson broke through in the fifth over when he removed Nick Gubbins' middle stump as the batsman played all round a straight one. Gubbins was playing his first match of the season after recovering from a hamstring injury.
Robinson dismissed the other opener, Sam Robson, in his next over, as the batsman nibbled at a fine delivery that moved away from him.
Sussex missed their first chance when Stevie Eskinazi, on 28, was dropped by Phil Salt at backward point off George Garton. Eskinazi had added ten runs before he was dropped again, this time in the slips off Robinson.
Sussex put down their third catch when Hilton Cartwright, on two, was dropped behind, a difficult diving attempt to the wicketkeeper's left off David Wiese.
But Eskinazi failed to make the most of his second escape. He had not added to his score when he was lbw to Robinson and the same bowler had Cartwright caught in the slips for four. Then, just before lunch, Robinson had Dawid Malan lbw for 13.
After the interval Holden and John Simpson added 56 in 18 overs for the sixth wicket before Simpson was caught on the deep midwicket boundary off Danny Briggs. It was soon 135 for seven when Harris was caught at point off the same bowler for a single. Ollie Rayner was then lbw, half-forward, to give Robinson his sixth wicket.
That left Middlesex in a very ordinary position at 169 for eight. But Holden, dropped on 28, found late order support from Murtagh and the pair put on 51 for the ninth wicket. Murtagh finally played a poor stroke and was caught by Luke Wright at mid-off. Robison completed his demolition work when he plucked out Tom Barber's off stump to leave Holden stranded.
But Middlesex fought back valiantly. Murtagh had Luke Wells and Salt well caught in the slips before Harris struck. First, he had Stiaan van Zyl caught by Eskinazi at third slip and then he bowled Luke Wright, shouldering arms, for nine.