Mason, who won the title last year at the same venue, defeated Ratcliffe by two holes after having been two down at the turn.
The Englishman birdied the 10th, 13th and 15th to gain control of the match and set up a quarterfinal encounter against Italian Guiseppe Cali, who beat Englandís Maurice Bembridge two and one.
ďAnother tough match. I am having to work hard to defend my title,Ē said Mason, who was taken to the 18th by Jamaican Delroy Cambridge in the opening round.
ďI played well and got the putter working properly on the back nine,Ē added Mason. Mason is presently in second place on the Seniors Tour Order of Merit list and trails American Pete Oakley by just Ä11,435. With Oakley now focusing on playing on the US Champions Tour Mason is well placed to recapture top spot this week. He claimed last yearís Merit list title after four victories in a brilliant rookie season.
The upset of the day came when Englandís Nick Job defeated Argentinean Luis Carbonetti. In form Carbonetti won the Bovis Lend Lease European Senior Masters last weekend, and the Digicel Jamaican Classic in association with Sony Ericsson earlier this season, and was one up playing the 18th.
However, Job rammed home a 25 footer for birdie on the last to send the match into sudden death and later triumphed when Carbonetti bogeyed the 22nd hole.
Job will face Chileís Guillermo Encina in the next round. Encina overcame Englandís Malcom Gregson on the 21st hole.
Scotlandís John Chillas looking for his first win of the year after three second place finishes beat American Jerry Bruner by the comfortable margin of 4&2.
Chillas was five up at the turn as Bruner had a poor outward half of four over par. The Scot will line up against Japanís Seiji Ebihara, who knocked out Frenchman Gery Watine.
Englandís Bob Cameron produced a scintillating finish to overcome compatriot Ian Mosey by two holes. Cameron, who won for the first time on the Seniors Tour this season at the Open de France Seniors, was one down with four to play but triumphed by finishing with an eagle on the 15th, and birdies on the 16th and 18th.