Voges, Whiteman give WA the lead

Former Test opener Ed Cowan was forced off the field after being struck on the head by a Joel Paris bouncer in NSW's Sheffield Shield match against Western Australia in New Zealand.

Cowan was on two when he copped a rising delivery from Paris in the seventh over of the Blues' second innings, taking a few minutes to regather himself before team officials advised him to leave the field.

WATCH: Ed Cowan struck by Paris bouncer

A Cricket Australia spokesperson offered this statement after play. 

"Ed suffered a hit to the front of his helmet during his batting innings. As per the Cricket Australia concussion guidelines he was assessed on the spot by the Cricket NSW doctor and retired from the game hurt.

"Advice from the doctor is that Ed's health is in a reasonable state but per the Cricket Australia concussion guidelines, he will be observed for the next 24 hours as a precautionary measure and not take further part in the match."

NSW batsmen Kurtis Patterson (5no) and nightwatchman Nathan Lyon (0no) took the offer of bad light in the next over with NSW on 1-11, still trailing the Warriors by 78 runs.

Test batsman Adam Voges, earlier on Friday's third day, had taken his strong Australian summer form to New Zealand with a majestic 149, leading his side past the Blues' first-innings total of 402.

Partnerships with Hilton Cartwright (36) and Sam Whiteman (93) helped WA surpass NSW's mark by tea, before Nathan Rimmington's 48 gave them the 89-run lead.

Highlights: Whiteman marks return with innings of 93

Resuming on his overnight score of 58, Voges survived an appeal for a catch in close from a Lyon delivery in the first session before celebrating his century off 218 balls by hooking Doug Bollinger to the boundary.

He was then run out by clever work from Ben Rohrer to fall just shy of the 150-milestone.

Voges is averaging 85.66 in Test cricket, and his unbeaten knock means he has struck 829 runs in his most-recent 10 innings at first-class or Test level.

Highlights: Voges warms up for Tests with 149

Lyon finished with figures of 3-146 off 45.5 overs, while former Test duo Bollinger and Trent Copeland, playing his first match in 18 months, also bagged three each.

Blues opener Daniel Hughes, who notched a half-century in the first innings, fell cheaply when he was bowled by Paris, who made the most of swinging conditions late in the day.

WATCH: Hughes leaves one he shouldn't have

Amazingly, both sides are guaranteed to claim 1.57 bonus points from the match, having had identical scores of 6-307 after 100 overs in each innings.