Ravi Bopara’s unbeaten 54 and debutant Tim Seifert’s quick-fire 35 helped Sussex chase down a DLS (Duckworth–Lewis–Stern) total of 146 in 17 overs, after rain delayed the start of the second innings.
Earlier, Middlesex imploded, losing eight wickets for just 62 runs in the second half of their innings. The visitors were cruising at 101-2 at the halfway mark before a crows of about 4,000.
After being put into bat by Sussex, Middlesex began their innings with intent and aggression from Max Holden’s reverse-sweep off the very first ball of the innings.
But the opener departed first ball next over, as Steve Finn had him caught at cover. Stevie Eskinazi and Joe Cracknell kept attacking in the powerplay.
Cracknell used his feet early to put Rawlins off his length, lofting him down the ground for six. Eskinazi found the gaps in the off-side with ease.
Eskinazi greeted Finn in the fifth over with three consecutive boundaries, but the bowler had the last laugh as the Middlesex skipper edged one to keeper Seifert after a quickfire 35.
Middlesex raced on to 71-2 at the end of the Powerplay. Ravi Bopara and Archie Lenham choked the flow of runs to some extent but Cracknell kept the score ticking. He pounced on bowlers missing their length by peppering the leg-side boundary.
Obed McCoy bowled into the breeze and picked up the wickets of Jack Davies and Martin Andersson with his bag of slower balls and cutters. He had Davies caught at deep-extra cover before finding the bottom edge of Andersson.
From the other end, young Lenham bowled with accuracy and control, finishing his quota with 0-26.
What followed was a dramatic collapse. Buoyed by some tight bowling, the Sussex fielders backed it up with some acts of pure brilliance.
Luke Wright led the way, diving to his right from short third man to dispatch Simpson. Finn bowled a very good second spell, varying his line and length effectively to finish with 3-29.
Cracknell meanwhile was picking the odd boundaries and completed a sensational half-century. After flaying Tymal Mills over deep backward square for 6, he mistimed a hoick and Jack Mills gleefully hung on to a skier. Cracknell ended with 68.
McCoy returned to polish off the lower-middle order and impressed once again, ending up with 4-30.
First Luke Hollman and then Toby Roland-Jones found the safe hands of Delray Rawlins in the deep, as the wickets kept tumbling. Captain Ravi Bopara got into the act and held on to a wonderful catch.
Some late fireworks from Aussie Chris Green pushed Middlesex to 163. The final five overs yielded only 36 for Middlesex but they lost five wickets in that interval.
Nobody barring Cracknell, Eskinazi and Green got going for the visitors and a mixture of calamitous batting and good bowling restricted the visitors after their blistering start.
With a small burst of rain prompting the target to be revised to 146 off 17 overs, the Sussex line up threw caution to the wind.
In a deja vu moment, the first over began with a boundary and the second over began with a wicket. Roland Jones sent Wright back before Jason Behrendorff produced a jaffa to get rid of Ali Orr.
Seifert kept the runs flowing by stroking some pleasant-looking boundaries. The Kiwi is a natural timer and displayed his acumen throughout his knock of 35.
Tom Alsop failed to keep his run of form going, top-edging Roland-Jones to leave Sussex precariously poised at 59-3 after six overs.
But a poor over from Hollman gave Sussex all the impetus they needed to better their scoring rate.
Anderssen trapped Seifert LBW and Rawlins did not last for long, succumbing to Green. Bopara and Harisson Ward were cautious while facing Thilan Walallawita, running well between the wickets, but launched into Roland-Jones, who conceded 16.
Ward lofted a massive six down the ground and nudged the next delivery for a boundary, while Bopara punished a loose short delivery for four. Behrendorff mixed his pace, conceding just five and finishing with figures of 1-23.
Sixteen were needed off the final two overs. Green bowled a tidy penultimate over, conceding just six by bowling flat and not letting the batsmen get underneath the ball.
Anderssen was tasked with defending 10 off the final over. But Bopara reserved his best for the end, picking the bones out of a slower ball, launching it for six over long on and finished things with a glance past square leg. The duo of Bopara and Ward added 58 in just 41 for the sixth wicket.
Sussex have now won three in three, catapulting them up to fourth in the South Group. They face a daunting trip to Surrey next – on Wednesday (8 June). Middlesex taste defeat for the first time after winning three on the bounce. They host Hampshire next Tuesday.