Alexei Kervezee was Worcestershire's unexpected hero with the ball with a three wicket burst on the third day of the LV = County Championship clash with Sussex at Hove which remains evenly poised at tea.

Kervezee scored a fine 93 in the Worcestershire first innings and followed that up with the notable scalps of first innings century-maker Matt Machan, the in-form Luke Wright and Sussex skipper Ed Joyce with his off spin.

They were his first wickets for the county with his previous two first class victims achieved for Holland against Scotland and Namibia in 2007 and 2008.

Charlie Morris was also rewarded for some aggressive and fine bowling with two wickets.

But half centuries from Machan and Joyce kept Sussex in contention.

Morris was quickly into his stride and broke through in the third over of the morning. Luke Wells (4) was undone by a lifting delivery and Alex Gidman at first slip held onto a sharp catch away to his right with the total 10-1.

Jack Shantry continued to share the new ball and was swept for six by Joyce.

Machan survived a difficult chance to Tom Fell at third slip off Morris when on four. Morris was troubling both batsmen and Joyce picked up a streaky boundary with an edge to third man.

Machan was less convincing than in his superb first innings knock but a straight drive for four off Andrew brought up the 50.

The all-rounder bowled three overs but then left the field but returned after a short spell and bowled three more overs between lunch and tea.

Joyce, who scored eight Championship centuries last season, reached his half century off 77 balls with seven fours and a six.

The century stand with Machan came up in 22 overs.

Kervezee came into the attack and troubled Machan immediately before trapping him lbw for 55 made off 79 balls with six fours. He added 119 in 27.1 overs with Joyce.

Morris enjoyed a second success with the second ball after lunch when Craig Cachopa was adjudged lbw for nought.

Kervezee continued to wheel away during the afternoon session and broke through again when Wright on 21 popped up a catch to Richard Oliver at short leg.

Then the 25-year-old accounted for the prized wicket of Joyce who edged to Tom Kohler-Cadmore at second slip.

Joyce's 82 had occupied 149 balls and contained seven fours and one six.

Kervezee was eventually rested after a spell of 15-1-47-3 and his replacement Shantry bowled Ben Brown for 44 with a ball that skidded on with Sussex then 233-6.

They added two more runs and at tea had an overall lead of 191.