Imran Tahir got a breakthrough for the Proteas. Photo: Peter Cziborra/Reuters

LONDON Pakistan were pegged back after making a strong start in their must-win World Cup clash against fellow strugglers South Africa at Lord's on Sunday.

After Pakistan captain Sarfaraz Ahmed won the toss and decided to bat first, Fakhar Zaman and Imam-ul-Haq put on 81 for the first wicket.

Zaman was the first man out when he was caught by Hashim Amla off Imran Tahir for a 50-ball 44 that featured six fours and one six.

Pakistan were still well set at 97-1 after 20 overs, with Imam unbeaten on 44 and Babar Azam seven not out.

But Imam was out in the following over, caught and bowled by Tahir without adding to his score.

With only one win apiece, Pakistan and South Africa both need a victory to keep alive their slender hopes of qualifying for the semi-finals.

Beaten by bitter rivals India in their last match, Pakistan's beleaguered players spent the past week involved in a series of spats with frustrated fans both in person and on social media.

It was reported Pakistan stars Imam and Babar responded to abuse by pushing their tormentor, while Sarfaraz was said to have been taunted while shopping with his family.

Sarfaraz had urged Pakistan supporters to get behind the team, but for that to happen they needed a good start.

Fakhar and Imam did their best to oblige.

Fakhar slapped Kagiso Rabada's second ball of the match through the covers for a tone-setting four.

Imam followed suit with three crunching fours off Lungi Ngidi's second over.

The green-shirt-clad Pakistan fans who made up the majority of the crowd were on their feet cheering when Fakhar's effortless six off Ngidi made it 44-0 from the first six overs.

Fakhar had a narrow escape when he slogged Chris Morris to Tahir, who claimed he made the catch after running in from the boundary.

The umpires asked for a review that showed the Pakistan-born South African's fingers were not under the ball as it hit the turf, earning Tahir jeers from the crowd as he returned to his position following the not out decision.

Proteas captain Faf du Plessis was furious and when Imam hit the next ball for four, just past the sprinting Tahir, the Pakistan flag-waving frenzy in the stands reached fever pitch.

Tahir was booed when he came on to bowl, but the leg-spinner got his revenge when Fakhar attempted a bizarre scooped shot that saw him caught in the slips by Amla.

Not surprisingly, Tahir's trademark celebration sprint around the pitch seemed a little more vigorous than usual.

AFP