Ipswich cannot fail to win at the moment - no matter what their line-up, formation or opposition. Third in the Premiership is testament to their progress this season, and goals from Titus Bramble and David Johnson were enough to see off sorry Coventry for the second time in a week in last night's fourth-round tie.

The victory propelled George Burley's side into the quarter-finals, where they will meet either Manchester City or Wimbledon.

Burley's men are having their resources tested as well, with Matt Holland limping off at the interval and the manager having to tinker further with his side's tactics. Having ditched his wing-backs for the visit of the midlanders, his captain's knock encouraged him to narrow his side to a 4-3-3.

Whatever the numbers, Coventry were left counting the cost of Youssef Chippo's generosity in the build-up to Bramble's opener. He made amends by winning a penalty, converted by Craig Bellamy, but his earlier slip proved decisive.

Both sides chose to rest scorers from the weekend - Ipswich's nine-goal marksman Marcus Stewart and Coventry captain Mustapha Hadji.

Ipswich wasted no time in taking the lead. There appeared no apparent danger as Chippo seized on a loose ball inside his own area following a corner. But, instead of clearing, the Moroccan midfielder attempted to dribble and succeeded only in teeing up Bramble.

The giant teenage centre-back gleefully slotted the ball inside Chris Kirkland's near post from 10 yards.

Yet seconds after that sixth-minute howler, Chippo almost equalised with a brilliant 30-yard volley which Keith Branagan acrobatically tipped over the bar.

Bramble may have added his second for Town as he again found space in the area, but his header from a Martijn Reuser corner flew the wrong side of Kirkland's left-hand post.

Ipswich continued to dominate possession, yet David Thompson went close with speculative free-kick from the left which brushed the roof of the net.

Coventry's former Norwich striker Bellamy - roundly jeered by the home fans on his return to East Anglia remained the visitors' most likely threat.

His pace and skill set him free on the right-hand by-line and forced Branagan to smother a 31st-minute cross-shot at the feet of John Aloisi.

A raking pass from former Liverpool man Thompson then split the Ipswich defence for the breaking John Eustace. He controlled the ball on his chest and volleyed on the turn, but Coventry's goalscoring hero in the last round at Southampton hit his effort straight into Branagan's midriff.

Ipswich had started the second period the better, yet Coventry found an equaliser through a swift breakaway.

Chippo, villain of the piece earlier, raced into the area - and Fabian Wilnis' challenge sent the Moroccan to the turf.

Referee Paul Durkin pointed to the spot, and Bellamy's two-step shuffle of a penalty sent Branagan the wrong way.

But Johnson eventually found his range after seizing on a long ball, striding into the area in the 65th minute, evading Williams' desperate last-gasp challenge and sliding a left-foot shot under Kirkland for Ipswich to regain the advantage.

Ipswich: Branagan, Wilnis, Clapham, Bramble, Scales, Hreidarsson, Holland, Johnson, Reuser, J Wright, Scowcroft. Subs: Salmon, Stewart, Croft, Karic, Logan.

Coventry: Kirkland, Breen, Williams, Konjic, Quinn, Telfer, Eustace, Thompson, Chippo, Bellamy, Aloisi. Subs: Hedman, Hadji, Palmer, Zuniga, Strachan.

Referee: P Durkin (Dorset)