Pompey extended their unbeaten run to 11 games but conceded two points when they allowed battling Watford to hit back with an equaliser ten minutes from time.
Redknapp said: "We have had a succession of hard games and we have come from behind to win games this season so we can hardly complain when a side does it to us.
"We felt comfortable at half time, having passed the ball well and looked the better side but Watford really tore into us after the interval and we had a few close calls before we fell behind."Redknapp's major concern is the loss of Arjan De Zeeuw who limped off with a knee ligament injury after only five minutes.
That leaves Portsmouth short of central defenders as they have Linvoy Primus playing in pain and needing a hernia operation.
Watford had the better of the early exchanges before Pompey hit their rhythm with skipper Nigel Quashie and striker Svetoslav Todorov going close.
Towards the end of the half, Watford striker Gifton Noel-Williams had a shot blocked as he pounced on a loose ball at the near post and Portsmouth were glad to concede a corner.
Watford tore into Portsmouth after the break with Jermaine Pennant tormenting them on the right.
From one cross, Heidar Helguson headed wide at the far post and was unlucky to see another effort bounce away when he met a cross from Pennant.
Marcus Gayle had a header cleared off the line before Watford finally broke through after 50 minutes.
Pennant's cross eventually fell to Jason Crowe facing his own goal and, as he hesitated, Micah Hyde nipped in to score.
Three minutes later Pompey were on terms with Kevin Harper, Todorov and Quashie combining to provide Deon Burton with a chance from close range.
Five minutes later Pompey took the lead when a clearance by Alec Chamberlain was headed back into the penalty area by Quashie and Harper scored a superb goal, curling the ball in at the far post.
But Watford hit back and scored from a set piece after 80 minutes when substitute Allan Nielsen's long throw was nodded on by Wayne Brown and skipper Neil Cox was able to pick his spot with the header.