Ian Humphreys missed three conversions and Irish threatened to steal an improbable win as Sailosi Tagicakibau's try and four Delon Armitage penalties brought the Exiles to within three points.

But White crashed over with seven minutes remaining to put Leicester in the top four for at least 24 hours.

Marcelo Loffreda rung the changes for the Exiles' visit, making a total of 12 changes and the shake-up seemed to have the desired effect with skipper Louis Deacon making inroads with an early break.

And the Tigers grabbed the lead on seven minutes after some clever work by New Zealand centre Aaron Mauger led to full-back Vesty finishing coolly in the corner.

Humphreys converted but London Irish hit back on 24 minutes as Tagicakibau finished a move involving nearly the whole of the back line.

Armitage missed the conversion but made amends with a 30-minute penalty only for Humphreys - taking fly-half duties in place of Andy Goode - to respond in kind.

Johne Murphy missed a golden opportunity to put Rabeni away after miscuing his pass but the Fijian flyer did cross a minute before the break.

This time Vesty was the provider as his perfectly-weighted grubber kick was pounced on by Rabeni.

But another Armitage penalty pegged the Tigers back and made the half-time scorer 15-11.

Irish had the wind behind their backs in the second half but it was the power of Leicester's pack which told as they went through the phases inside the Exiles' 22.

Tom Varndell, on as a blood replacement for Rabeni, seemed set to grab his eighth try of the season only for referee Tony Spreadbury to pull play back for a penalty.

The Tigers though were not to be denied and after winning a lineout right on the Exiles tryline, Italian prop Castrogiovanni crashed over.

Humphreys though missed the conversion and he would be made to pay as two Armitage penalties brought London Irish to within three points.

The visitors sensed only their second win at Welford Road in 84 years only for White to seal the win with seven minutes remaining.

In near gale-force winds Humphreys missed the conversion but the Tigers were able to hold Brian Smith's side at arm's length until the final whistle.