|Leicester (9) 33|
|Tries: Toomua, Kitchener, Thomstone Cons: Toomua 3 Pen: Toomua 4|
|Harlequins (8) 18|
|Tries: Alofa, Wallace, Matthews Pen: Smith|
Matt Toomua produced a virtuoso display on his first start at fly-half for Leicester, scoring 23 points to steer Tigers past Harlequins at Welford Road.
The Australia utility back's boot kept the game tight for the first hour before he spotted a gap on the 22 to burst away for the hosts' first try.
Toomua's cross-field kick fell kindly for Graham Kitchener to go over before Adam Thomstone intercepted and scored.
Harlequins replied through Alofa Alofa, Luke Wallace and Charlie Matthews.
The scoreline was tough on Quins, who led 13-9 after an hour but ultimately were blown away in the final quarter of the match to suffer a serious dent to their play-off ambitions.
Leicester closed to within five points of the top four as Toomua pulled the strings and inspired Tigers to their eighth win of the season.
The 28-year-old saw space between two forwards to race over before his chip into space on the right wing bounced kindly for Sione Kalamafoni and Kitchener rolled over the line.
Yet for much of the game Tigers struggled to break down a spirited Harlequins defence that was vastly improved from conceding six tries to 14-man Wasps last week.
The visitors scored with their first attack as Aaron Morris made an outside break to send Alofa into the right corner.
After half-time, and with Marcus Smith in the sin bin, they went through 24 phases before Morris' floated pass to Wallace on the right wing saw the flanker score Quins' second try - but their lead was soon swept away.
Leicester director of rugby Matt O'Connor told BBC Radio Leicester:
"To finish the game like we did and dominate the last 20 minutes was really pleasing and gives us a lot of confidence moving forward.
"Matt Toomua managed the game really well with Sam Harrison and we had a lot more momentum and broke them down slowly.
"For a guy who hasn't played much at 10 recently, he was outstanding. He kicked the ball well for us, was instrumental in two tries and moved the Quins defence around."
Harlequins director of rugby John Kingston:
"I thought for an hour we were comfortable and the better side, we had a penalty count that was against us and it's very tough to win a match when it's like that.
"You always say you have to be 10-15 points better to win at a place like this and I think it is really harsh to not get the win today.
"It's disappointing as we want to be in the mix and the top six is now definitely our goal and we want to get there like we did last year.
"I'm really proud of the team, I don't feel sorry for them but it's harsh on them, that they've come away with nothing because for large periods of the game we were the better side."
Leicester: Veainu; Thompstone, Tuilagi, Owen, Holmes; Toomua, Harrison; Bateman, Youngs (capt), Mulipola, Fitzgerald, Kitchener, Williams, O'Connor, Kalamafoni.
Replacements: Polota-Nau, Rizzo, Cilliers, Wells, Hamilton, Simmons, Ford, Tait.
Harlequins: Morris; Alofa, Marchant, Roberts, Visser; Smith, Kitto; Boyce, Gray, Sinckler, South, Matthews, Wallace, Ward (capt), Chisholm.
Replacements: Piper, Lambert, Collier, Twomey, White, Lewis, Lang, Ibitoye.
Referee: Wayne Barnes.