Defending King Edward VII Gold Cup champion and current World Match Racing Tour leader Ian Williams (2-2) virtually nosedived in Hamilton harbour yesterday.

The world's number one ranked match race skipper lost a crucial battle with Americas Cup winner Ed Baird (4-0) and was then beaten by Portugal's Alvaro Marinho (2-2), leaving the defence of his title hanging in the balance with two flights remaining in the round robin phase of the regatta.

"We had a shocker today, really," the 30-year-old Englishman lamented. "We had a few problems getting into a boat we haven't sailed before and struggled with the set-up for Ed (Baird) who was just faster today."

Williams' afternoon then turned from bad to worse as he again came up short against Marinho after surrendering the lead on the final downwind leg.

"We were leading the last run and then made a silly mistake and he (Marinho) just rolled us into the finish," he added.

The unflappable Baird stretched his unbeaten streak to four yesterday with victory over the defending champ in his one and only flight to move onto the verge of advancing through to the quarter-finals.

"We just tried to connect the dots on the harbour with the puffs and that was the difference," he said.

The Gold Cup hopes of Glenn Astwood (4-1) and Blythe Walker (4-1) also gathered momentum yesterday, with the local pair now within striking distance of progressing to the last eight.

Brazilian Daniel Glomb and England's Robbie Allam proved to be no match for Astwood in Group C, while Walker also continued to impress in Group A where he recorded victories over Denmark's Peter Widbroe (0-4) and New Zealand's Scott Dickson (2-3).

Astwood will now square off against England's David Tabb (0-4) today knowing that a victory could automatically catapult him through to the quarter-finals, while a win for Walker over Americas Cup winner Baird coupled by any further slip ups by either Williams or Marinho will also see the 1992 Olympian safely through to the next round without having the extra burden of facing off in the Repechage that will decide the seventh and eighth quarterfinalists.

Italy's Paolo Cian (4-0) currently leads Group C with Brazil's Glomb (3-1), Sweden's Bjorn Hansen (2-2) and American Brian Angel (2-2) also still in the hunt.

For veteran skipper Astwood, a blend of enthusiam and experience have culminated in success thus far in the prestigious regatta.

"Hopefully we can continue this success. David (Tabb) seems to be struggling a bit at the moment. But we are going to go out there and treat him as we do anybody else, attack when we can and see where we end up from there."

Walker is wary of the threat from Baird, but remains cautiously optimistic he can overcome the next hurdle and advance to the last eight for the second straight year.

"It feels good to be in this position, but we still have our work cut out for us as we are not through yet," he said. "We have to face Ed (Baird) tomorrow (today) and we are looking forward to that.

"He has won all of his races and obviously is sailing very well. But we are looking forward to sailing against him as we pretty much need to beat him to go through. If we don't, then it's all in Ian Williams' hands."

Finland's Staffan Lindberg (4-0) currently tops Group B followed by last year's Gold Cup runner up Mathieu Richard (3-1) of France in second place respectively.

Sweden's Johnie Berntsson (2-2) and Finland's Jon Eriksson are among those in Group B with an outside chance of gaining one of two automatic quarter-final berths.

King Edward VII Gold Cup racing continues today in Hamilton harbour followed by the start of the Renaissance Re Junior Gold Cup in the Great Sound.