Imam said the 41-run defeat against defending champions Australia earlier in the competition was painful.
Pakistan could still make the semis, provided they win their remaining three games.
In the first World Cup game at Lord's, Pakistan won the toss and put up a good total.
His 'three dimensional' ability was put to test against Pakistan and he responded with wickets of opener Imam-ul-Haq and rival captain Sarfaraz Ahmed.
Pakistan opener Imam-ul-Haq described the World Cup match against India on Sunday as a "huge-pressure game".
David Warner's 15th ODI hundred sets up Australia's 41-run win over Pakistan in Taunton.
Having lost against India in their previous game, the Aaron Finch-led Australia side returned to winning ways.
Pakistan can take some heart from that fact that they swept Pakistan 5-0 two months ago in the UAE.
Imam said the confidence he had gained from facing England quicks Jofra Archer and Mark Wood would help him tame the Australia attack.
With a 14-run win over England, Pakistan ended their 11-match losing streak.