Olonga, an 18-year-old who was no-balled four times for throwing while playing for a President's XI against the Pakistanis last week, removed Saeed Anwar after coming on as first change as Pakistan made 51 for 1 in reply by the close. His victim was caught down the legside by wicketkeeper Andy Flower, who had earlier helped set a record for a Test partnership between brothers.
Andy, who scored a century, and brother Grant, who compiled a maiden double-century, carried on where they had left off the previous evening and extended their fourth-wicket stand to 269. That was five runs better than the previous highest, set by Australia's Ian and Greg Chappell against New Zealand in Wellington in March 1974.
Andy Flower finally went, caught in the gully by Wasim Akram off Kabir Khan for 156, scored off 245 balls and including 18 fours and one six. His brother, however, remained unbeaten on 201 after an innings of just under 11 hours. He faced 522 balls and hit 10 fours and one six.
He found an able partner in Guy Whittall, who rode his luck in the early stages to post his first Test century. Dropped on 24 and 98, Whittall finished on 113 not out, helping Zimbabwe to their highest Test score. It bettered the 462 for 9 they made against Sri Lanka in Bulawayo in October.
(Second day; Zimbabwe won toss)
Zimbabwe - First Innings (overnight: 289 for 3)
G Flower not out 201
*A Flower c Wasim Akram b Kabir Khan 156
G Whittall not out 113
Extras (b4 lb19 w3 nb22) 48
Total (for 4 dec) 544
Fall (cont): 4-311.
Did not bat: S Carlisle, H Streak, P Strang, D Brain, H Olonga.
Bowling: Wasim Akram 39.5-12-95-1; Aaqib Javed 34.1-8-73-2; Kabir Khan 35-5-142-1; Salim Malik 9-0-42-0; Akram Raza 34-6-112-0; Asif Mujtaba 7-0-30-0; Aamir Sohail 6-1-27-0.
Pakistan - first innings Aamer Sohail not out 28
Saeed Anwar c A Flower b Olonga 8
Akram Raza not out 8
Extras (1b 1lb 1nb 4w) 7
Total (for 1) 51
Bowling (to date): Streak 7-0-21-0; Brain 4-1-17-0; Olonga 3-0-11-1.