Guinness Pro 12 leaders Connacht held off a spirited Edinburgh fightback to claim a hard-fought 28-23 victory on Friday night.
Connacht's tries came from AJ MacGinty, Jake Heenan, Bundee Aki and Eoin McKeon, with Craig Ronaldson kicking three conversions and McGinty one.
The hosts trailed 14-0 at the break, but closed the gap to just a point in the second half as Chris Dean, Damien Hoyland and Cornell Du Preez all touched down and Sam Hidalgo-Clyne landed one conversion plus two penalties. However, their comeback fell just short.
Reigning champions Glasgow Warriors consolidated their bid for a top-four finish by beating Cardiff Blues 27-20 at Scotstoun on Sunday.
After a bright opening that brought Glasgow a try from prop Gordon Reid, the game fell away until the Warriors closed out the half with a try from lock Tim Swinson. Duncan Weir converted both scores as well as kicking two penalties to send his side into the break with an impressive 20-0 lead.
The second half only came alive in the last 10 minutes. In that period Cardiff scored three tries through winger Dan Fish, flanker Ellis Jenkins and replacement Macauley Cook but Glasgow were able to protect their lead thanks to a try from flanker Simone Favaro as the hosts held on for the win.
Leinster kept in sight of the leaders Connacht when they maintained their 100 percent home winning record with a 19-16 defeat of Ospreys at the RDS.
Leo Cullen's men made hard work of it, though, scoring a lone penalty from Ian Madigan in the final 50 minutes as the Ospreys launched a stirring second-half fight-back. Dan Leavy's second try in as many games, converted by Ian Madigan who also landed three penalties, had the hosts leading 16-3 at half-time.
Sean Cronin and man of the match Ben Te'o stood out in attack for Leinster whose defence managed to frustrate the Welshmen until Dan Baker's 60th-minute touchdown.
Sam Davies converted, adding to his two earlier penalties, to put just three points between the sides. Madigan and Davies swapped further kicks, but Leinster did just enough to hold on in a nail-biting climax.
The result sees Leinster keep the pressure on provincial rivals Connacht at the top of the table, while it was a further dent to the Ospreys' top-four and Champions Cup qualification hopes.
Munster kept up their pursuit of the title with a 26-5 thrashing of struggling Dragons at Thomond Park.
The hosts were 19-0 up thanks to a try from Rory Scannell and a brace from Dave Kilcoyne - two converted - before the Newport side got on the board through Hallam Amos. James Cronin completed the victory for the Irish region.
Elsewhere on Friday, Scarlets strengthened their playoff drive but they were made to work hard for a 24-15 victory by bottom side Benetton Treviso at Parc y Scarlets.
The West Walians had appeared to be in for a comfortable evening when wing Steffan Evans and flanker James Davies gave them an early 14-0 lead.
But the Italians battled back with two tries from number eight Robert Barbieri and led 15-14 with 12 minutes left on the clock.
However, as they have done for most of the season, Scarlets managed to pull another win out of the hat with man-of-the-match Evans racing over for his second try to seal the victory.
Ulster bounced back from two consecutive defeats to get their play-off ambitions back on track with a 32-0 bonus-point victory over Zebre at the Kingspan Stadium.
The home side scored four tries with Nick Williams crossing twice in the first half before Peter Browne and replacement Paul Marshall went over after the break to keep them in fourth place.
Paddy Jackson added 12 points with the boot from two penalties and three conversions, while Ulster had another three tries disallowed.