England's Joe Root celebrates after scoring a double century during the fourth day of the first test cricket match between Pakistan and England, in Multan, Pakistan. (AP )

MULTAN, Pakistan, Oct 10, (AP):  England is on the verge of a famous cricket victory after Harry Brook smashed the second-fastest triple century in test history, Joe Root scored a career-best 262 and the tourists declared their first innings at an enormous 823-7 against Pakistan in the first test on Thursday.

Pakistan, which scored 556 in its first innings, collapsed the second time round to reach stumps on Day 4 at 152-6, needing another 115 runs to avoid an innings defeat. It was the fourth time a test team scored more than 800 runs - and the first time this century - as Yorkshire pair Brook and Root showed plenty of resilience and stamina to rewrite the record books in the heat of Multan.

"It was an unreal wicket to bat on and I’ll probably roll it (the wicket) open and take it with me,” Brook said after his marathon seven-hour innings of 317 runs off 322 balls that featured 29 fours and three sixes. Brook raised his triple hundred off 310 balls, which was the second-fastest in test history after Virender Sehwag of India achieved the feat in 268 balls against South Africa in 2008.

"Me and Rooty both were just trying to cash in on what was a good pitch," Brook said. "We were both struggling with the heat for a while, (but) it makes you feel so comfortable when you watch him at the other end, he makes the game look so easy.” Brook was one of England's key batters during its 3-0 sweep in Pakistan two years ago when he scored centuries at Rawalpindi, Multan, and Karachi. Brook shared England’s highest-ever partnership of 454 runs with Root for the fourth wicket, taking the team from 249-3 to 703-4 in a marathon stand.