Andrew Strauss has described England's defeat against Pakistan in Abu Dhabi as among the most painful of his career.

Strauss, the England captain, top scored with 32 as his side was dismissed for 72 in pursuit of a target of 145. It was England's lowest total against Pakistan and only the second time they failed to chase a target of under 150 in the fourth innings in more than a century. The result condemned them to their first series defeat since losing in the West Indies in 2009 and jeopardised their reign as the world's No. 1 Test team. If England fail to win the final Test and South Africa inflict a 3-0 defeat upon New Zealand, then South Africa will usurp England.

To make the defeat all the more galling, England had several opportunities to win. Not only was their target modest but, had Kevin Pietersen hit the stumps with a simple throw on day three to run out Asad Shafiq, Pakistan's key second-innings partnership would have been ended. In the context of a low-scoring game, the extra 49 runs the pair added were vital.

"It is a struggle to think of a loss that has hurt more than this," Strauss said. "It's bitterly disappointing to lose a game you should have won. These are the games that hurt the most, because you feel like you've done everything you can to win the game - and then you aren't able to nail the final nail in the coffin.

Strauss' disappointment was increased by the sense that England had failed a significant challenge. Winning in Asian conditions remains the Holy Grail for England and, after the success of the last couple of years, they felt they had an excellent opportunity on this tour. He was, however, frank when assessing where England had gone wrong.

"I said at the start of this tour, this is the final frontier," Strauss said. "England teams haven't done very well out here [in Asia] in the past. We felt like we had a great chance to win this series, but I think the fact that we got rolled over twice in Dubai meant that there was some baggage there going into this final innings. Test cricket is hard and it exposes any vulnerability or weaknesses you have.

"As a batting unit we have to hold our hands up and say we haven't done well enough. We have been rolled over three times in four innings this series. There are no excuses - we need to be better than that.

"We just didn't play well enough, individually or collectively. Individually we've not been clear enough in our game plans against spin, we've not been clear enough in our methods of where our scoring areas are, and we've allowed pressure to build."

Strauss admitted that England's cautious approach might have contributed to the defeat. England were almost strokeless at times, with Alastair Cook labouring for 15 overs for his seven runs.

"It is easy to get caught between two stools," Strauss said. "You don't know whether to be patient or to take the bull by the horns. There is always a balance to strike between attack and defence and ultimately we didn't do it right. I'm a strong believer that players should play their natural game in positions like this, but it was a bit unfortunate that our attacking players were out very quickly."

Strauss was also keen to credit Pakistan for their performance. "It's very important in circumstances like this, and particularly after this game, to give a lot of credit to Pakistan," he said. "They were outstanding. They've been a good, close-knit unit - and they've got some very good spin bowlers. Ultimately, they've played better cricket than we did."

George Dobell is a senior correspondent at ESPNcricinfo