text: The Scotland international, 24, reached a century from just 70 deliveries and hit 18 boundaries and four sixes, as Sussex were all out for 345.
  Sri Lankan spinner Sachithra Senanayake (2-79) led Worcestershire's fight back with two wickets in two balls.
  Daryl Mitchell and Richard Oliver saw off the new ball to end the day without loss on 45.
  Machan's fireworks came after Luke Wells was dismissed early, caught at third slip playing a loose shot to Chris Morris.
  The number three attacked immediately, bringing up his half-century in 27 balls, before captain Ed Joyce (59) was dismissed by Jack Shantry (2-86).
  Luke Wright continued his good form (51) but Sussex's lower order, with the exception of Ajmal Shahzad (45*), struggled once Machan was caught by Mitchell.
  Senanayake picked up his first wicket for Worcestershire when he had Ashar Zaidi caught by Tom Fell, before trapping Steve Magoffin lbw next ball.
  Sussex's tail struggled to push the team towards 400, with Gareth Andrew bowling well to dismiss Tymal Mills and Matthew Hobden cheaply.
  Worcestershire had a scare shortly before stumps when opener Mitchell (18 not out) edged Shahzad to Joyce at second slip, but the Sussex captain was unable to cling on to the low chance.
  Sussex batsman Matt Machan:
  "I play better when I'm aggressive and go for my shots and it is something I have worked on.
  "I'm trying to take my game forward in red-ball cricket by playing more positively.
  "I only knew I was playing this morning so I decided to be aggressive from the start and once I'd got myself in I really enjoyed myself."
  Worcestershire director of cricket Steve Rhodes:
  "When a batsman hits the ball as sweetly as Matt did,  it can be difficult to bowl at.
  "It was a special innings because he climbed into some really good balls. We were a bit shocked by the onslaught.
  "I was pleased we managed to drag it back a bit after he chipped one up. It's a good cricket wicket. There is some pace there but you can score quickly."
target: A career-best 135 from Matt Machan formed the backbone of Sussex's innings against Worcestershire at Hove.